Aryl Ether-Base Kinase Inhibitors

ABSTRACT

The present disclosure is generally directed to compounds which can inhibit AAK1 (adaptor associated kinase 1), compositions comprising such compounds, and methods for inhibiting AAK1.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 61/608,737 filed Mar. 9, 2012.

The present disclosure is generally directed to compounds which caninhibit adaptor associated kinase 1 (AAK1), compositions comprising suchcompounds, and methods for inhibiting AAK1.

Adaptor associated kinase 1 (AAK1) is a member of the Ark1/Prk1 familyof serine/threonine kinases. AAK1 mRNA exists in two splice forms termedshort and long. The long form predominates and is highly expressed inbrain and heart (Henderson and Conner, Mol. Biol. Cell. 2007, 18,2698-2706). AAK1 is enriched in synaptosomal preparations and isco-localized with endocytic structures in cultured cells. AAK1 modulatesclatherin coated endocytosis, a process that is important in synapticvesicle recycling and receptor-mediated endocytosis. AAK1 associateswith the AP2 complex, a hetero-tetramer which links receptor cargo tothe clatherin coat. The binding of clatherin to AAK1 stimulates AAK1kinase activity (Conner et. al., Traffic 2003, 4, 885-890; Jackson et.al., J. Cell. Biol. 2003, 163, 231-236). AAK1 phosphorylates the mu-2subunit of AP-2, which promotes the binding of mu-2 to tyrosinecontaining sorting motifs on cargo receptors (Ricotta et. al., J. CellBio. 2002, 156, 791-795; Conner and Schmid, J. Cell Bio. 2002, 156,921-929). Mu2 phosphorylation is not required for receptor uptake, butphosphorylation enhances the efficiency of internalization (Motely et.al., Mol. Biol. Cell. 2006, 17, 5298-5308).

AAK1 has been identified as an inhibitor of Neuregulin-1/ErbB4 signalingin PC12 cells. Loss of AAK1 expression through RNA interference mediatedgene silencing or treatment with the kinase inhibitor K252a (whichinhibits AAK1 kinase activity) results in the potentiation ofNeuregulin-1 induced neurite outgrowth. These treatments result inincreased expression of ErbB4 and accumulation of ErbB4 in or near theplasma membrane (Kuai et. al., Chemistry and Biology 2011, 18, 891-906).NRG1 and ErbB4 are putative schizophrenia susceptibility genes(Buonanno, Brain Res. Bull. 2010, 83, 122-131). SNPs in both genes havebeen associated with multiple schizophrenia endophenotypes (Greenwoodet. al., Am. J. Psychiatry 2011, 168, 930-946). Neuregulin 1 and ErbB4KO mouse models have shown schizophrenia relevant morphological changesand behavioral phenotypes (Jaaro-Peled et. al., Schizophrenia Bulletin2010, 36, 301-313; Wen et. al., Proc. Natl. Acad. Sci. USA. 2010, 107,1211-1216). In addition, a single nucleotide polymorphism in an intronof the AAK1 gene has been associated with the age of onset ofParkinson's disease (Latourelle et. al., BMC Med. Genet. 2009, 10, 98).These results suggest that inhibition of AAK1 activity may have utilityin the treatment of schizophrenia, cognitive deficits in schizophrenia,Parkinson's disease, neuropathic pain, bipolar disorder, and Alzheimer'sdisease.

In a first aspect the present disclosure provides a compound of formula(I):

or a pharmaceutically acceptable salt thereof, wherein:

R¹ and R² are independently selected from hydrogen, C₃-C₆cycloalkyl, andC₁-C₃alkyl wherein the C₁-C₃alkyl is optionally substituted with one,two, or three groups independently selected from C₁-C₃alkoxy,C₁-C₃alkylamino, amino, cyano, C₁-C₃dialkylamino, halo, and hydroxy; or

R¹ and R² together are oxo; or

R¹ and R², together with the carbon atom to which they are attached,form an oxetane ring;

R³ is C₁-C₃alkyl-Y or C₂-C₈alkyl, wherein the C₂-C₈alkyl is optionallysubstituted with one, two, three, or four groups independently selectedfrom C₁-C₃alkoxy, C₁-C₃alkylamino, C₁-C₃alkoxyC₂-C₃alkylamino, amino,aryl, halo, C₁-C₃haloalkylamino, C₁-C₃haloalkylcarbonylamino, hydroxy,—NR^(x)R^(y), and C₃-C₈cycloalkyl, wherein the cycloalkyl is furtheroptionally substituted with one, two, or three groups independentlyselected from C₁-C₃alkoxy, C₁-C₃alkyl, C₁-C₃alkylamino,C₁-C₃alkoxyC₂-C₃alkylamino, amino, aryl, arylC₁-C₃alkyl, halo,C₁-C₃haloalkyl, C₁-C₃haloalkylamino and hydroxy;

R⁴ is selected from hydrogen, C₁-C₃alkoxy, C₁-C₃alkoxycarbonylamino,C₁-C₃alkyl, C₁-C₃alkylamino, C₁-C₃alkylcarbonylamino, amino, arylamino,arylcarbonylamino, C₃-C₆cycloalkylamino, C₃-C₆cycloalkylcarbonylamino,C₃-C₆cycloalkyloxy, halo, C₁-C₃haloalkoxy, C₂-C₃haloalkylamino,C₂-C₃haloalkylcarbonylamino, and hydroxy;

R⁵ is selected from hydrogen, C₁-C₃alkyl, cyano, C₃cycloalkyl, and halo;

R⁶ is selected from hydrogen, C₁-C₃alkyl, C₁-C₃alkylcarbonylamino,amino,

R⁷ is selected from hydrogen, C₁-C₃alkoxy, C₁-C₃alkyl, cyano, —CH₂OH,—CH₂OCH₃, CH(CH₃)OH, C(CH₃)₂OH, halo, and C₁-C₃haloalkyl;

R⁸ is selected from hydrogen, C₁-C₃alkoxy, cyano, and halo;

R^(x) and R^(y), together with the nitrogen atom to which they areattached, form a three- to six-membered ring; and

Y is selected from

wherein R⁹ is selected from hydrogen, C₁-C₆alkyl, C₃-C₆cycloalkyl, andC₁-C₆alkylcarbonyl;

n is 0, 1, 2, or 3;

each R¹⁶ is independently selected from hydrogen, C₁-C₆alkyl, aryl,arylC₁-C₃alkyl, C₃-C₆cycloalkyl, halo, and C₁-C₃haloalkyl; and

each R¹¹ is independently selected from hydrogen, C₁-C₃alkoxy andhydroxy.

In a first embodiment of the first aspect the present disclosureprovides a compound of formula (I), or a pharmaceutically acceptablesalt thereof, wherein R¹ and R² are each hydrogen.

In a second embodiment of the first aspect the present disclosureprovides a compound of formula (I), or a pharmaceutically acceptablesalt thereof, wherein wherein one of R¹ and R² is C₁-C₃alkyl and theother is selected from hydrogen and C₁-C₃alkyl.

In a third embodiment of the first aspect the present disclosureprovides a compound of formula (I), or a pharmaceutically acceptablesalt thereof, wherein one of R¹ and R² is hydrogen and the other isC₃-C₆cycloalkyl.

In a fourth embodiment of the first aspect the present disclosureprovides a compound of formula (I), or a pharmaceutically acceptablesalt thereof, wherein wherein R¹ and R² together are oxo; or R¹ and R²,together with the carbon atom to which they are attached, form anoxetane ring.

In a second aspect the present disclosure provides a compound of formula

or a pharmaceutically acceptable salt thereof, wherein:

R¹ and R² are independently selected from hydrogen, C₃-C₆cycloalkyl, andC₁-C₃alkyl wherein the C₁-C₃alkyl is optionally substituted with one,two, or three groups independently selected from C₁-C₃alkoxy,C₁-C₃alkylamino, amino, cyano, C₁-C₃dialkylamino, halo, and hydroxy; or

R¹ and R² together are oxo;

R³ is C₁-C₃alkyl-Y or C₂-C₈alkyl, wherein the C₂-C₈alkyl is optionallysubstituted with one, two, or three groups independently selected fromC₁-C₃alkoxy, C₁-C₃alkylamino, C₁-C₃alkoxyC₂-C₃alkylamino, amino, aryl,halo, C₁-C₃haloalkylamino, C₁-C₃haloalkylcarbonylamino, hydroxy,—R^(x)R^(y), and C₃-C₈cycloalkyl, wherein the cycloalkyl is furtheroptionally substituted with one, two, or three groups independentlyselected from C₁-C₃alkoxy, C₁-C₃alkyl, C₁-C₃alkylamino,C₁-C₃alkoxyC₂-C₃alkylamino, amino, aryl, arylC₁-C₃alkyl, halo,C₁-C₃haloalkyl, C₁-C₃haloalkylamino and hydroxy;

R⁴ is selected from hydrogen, C₁-C₃alkoxy, C₁-C₃alkoxycarbonylamino,C₁-C₃alkyl, C₁-C₃alkylamino, C₁-C₃alkylcarbonylamino, amino, arylamino,arylcarbonylamino, C₃-C₆cycloalkylamino, C₃-C₆cycloalkylcarbonylamino,C₃-C₆cycloalkyloxy, halo, C₁-C₃haloalkoxy, C₂-C₃haloalkylamino,C₂-C₃haloalkylcarbonylamino, and hydroxy;

R⁵ is selected from hydrogen, C₁-C₃alkyl, cyano, C₃cycloalkyl, and halo;

R^(x) and R^(y), together with the nitrogen atom to which they areattached, form a three- to six-membered ring; and

Y is selected from

wherein R⁶ is selected from hydrogen, C₁-C₆alkyl, C₃-C₆cycloalkyl, andC₁-C₆alkylcarbonyl;

n is 0, 1, 2, or 3;

each R⁷ is independently selected from hydrogen, C₁-C₆alkyl, aryl,arylC₁-C₃alkyl, C₃-C₆cycloalkyl, halo, and C₁-C₃haloalkyl; and

each R⁸ is independently selected from hydrogen, C₁-C₃alkoxy andhydroxy.

In a third aspect the present disclosure provides composition comprisinga pharmaceutically acceptable amount of a compound of formula (I), or apharmaceutically acceptable salt thereof, and a pharmaceuticallyacceptable carrier.

In a fourth aspect the present disclosure provides a method ofinhibiting adaptor associated kinase 1 (AAK1) activity, comprisingcontacting AAK1 with a compound of formula (I), or a pharmaceuticallyacceptable salt thereof.

In a fifth aspect the present disclosure provides a method for treatingor managing a disease or a disorder mediated by AAK1 activity, themethod comprising administering to a patient in need thereof atherapeutically effective amount of a compound of formula (I), or apharmaceutically acceptable salt thereof. In a first embodiment of thefifth aspect the disease or disorder is selected from Alzheimer'sdisease, bipolar disorder, pain, Parkinson's disease, and schizophrenia.In a second embodiment of the fifth aspect the pain is neuropathic pain.In a third embodiment of the fifth aspect the neuropathic pain isfibromyalgia or peripheral neuropathy.

Other aspects of the present disclosure may include suitablecombinations of embodiments disclosed herein.

Yet other aspects and embodiments may be found in the descriptionprovided herein.

BRIEF DESCRIPTION OF THE FIGURES

Aspects of the disclosure are illustrated in FIG. 1, which shows resultsobtained from a formalin pain model using AAK1 homozygous (−/−) knockoutmice and their wild-type (+/+) littermates. The AAK1 homozygous (−/−)knockout mice show a clear reduction in both acute and tonic painresponse as compared to their wild-type (+/+) littermates

This disclosure is based, in part, on the discovery that AAK1 knockoutmice exhibit a high resistance to pain. That discovery prompted researchthat ultimately led to the discovery of AAK1 inhibitors, compositionscomprising them, and methods of their use.

The description of the present disclosure herein should be construed incongruity with the laws and principals of chemical bonding. In someinstances it may be necessary to remove a hydrogen atom in order toaccommodate a substituent at any given location.

It should be understood that the compounds encompassed by the presentdisclosure are those that are suitably stable for use as pharmaceuticalagent.

It is intended that the definition of any substituent or variable at aparticular location in a molecule be independent of its definitionselsewhere in that molecule. For example, when n is 2, each of the twoR¹⁰ groups may be the same or different.

All patents, patent applications, and literature references cited in thespecification are herein incorporated by reference in their entirety. Inthe case of inconsistencies, the present disclosure, includingdefinitions, will prevail.

As used herein, the singular forms “a”, “an”, and “the” include pluralreference unless the context clearly dictates otherwise.

In some instances, the number of carbon atoms in any particular group isdenoted before the recitation of the group. For example, the term “C₁₋₆alkyl” denotes an alkyl group containing one to six carbon atoms. Wherethese designations exist they supercede all other definitions containedherein.

Asymmetric centers may exist in the compounds of the present disclosure.It should be understood that the disclosure encompasses allstereochemical isomeric forms, or mixtures thereof, which possess theability to inhibit AAK1. Individual stereoisomers of compounds can beprepared synthetically from commercially available starting materialswhich contain chiral centers or by preparation of mixtures ofenantiomeric products followed by separation such as conversion to amixture of diastereomers followed by separation or recrystallization,chromatographic techniques, or direct separation of enantiomers onchiral chromatographic columns. Starting compounds of particularstereochemistry are either commercially available or can be made andresolved by techniques known in the art.

Certain compounds of the present disclosure may also exist in differentstable conformational forms which may be separable. Torsional asymmetrydue to restricted rotation about an asymmetric single bond, for examplebecause of steric hindrance or ring strain, may permit separation ofdifferent conformers. The present disclosure includes eachconformational isomer of these compounds and mixtures thereof.

The term “compounds of the present disclosure”, and equivalentexpressions, are meant to embrace compounds of formula (I), andpharmaceutically acceptable enantiomers, diastereomers, and saltsthereof. Similarly, references to intermediates are meant to embracetheir salts where the context so permits.

The present disclosure is intended to include all isotopes of atomsoccurring in the present compounds. Isotopes include those atoms havingthe same atomic number but different mass numbers. By way of generalexample and without limitation, isotopes of hydrogen include deuteriumand tritium. Isotopes of carbon include ¹³C and ¹⁴C.Isotopically-labeled compounds of the disclosure can generally beprepared by conventional techniques known to those skilled in the art orby processes analogous to those described herein, using an appropriateisotopically-labeled reagent in place of the non-labeled reagentotherwise employed. Such compounds may have a variety of potential uses,for example as standards and reagents in determining biologicalactivity. In the case of stable isotopes, such compounds may have thepotential to favorably modify biological, pharmacological, orpharmacokinetic properties.

The compounds of the present disclosure can exist as pharmaceuticallyacceptable salts. The term “pharmaceutically acceptable salt,” as usedherein, represents salts or zwitterionic forms of the compounds of thepresent disclosure which are water or oil-soluble or dispersible, whichare, within the scope of sound medical judgment, suitable for use incontact with the tissues of patients without excessive toxicity,irritation, allergic response, or other problem or complicationcommensurate with a reasonable benefit/risk ratio, and are effective fortheir intended use. The salts can be prepared during the final isolationand purification of the compounds or separately by reacting a suitablenitrogen atom with a suitable acid. Representative acid addition saltsinclude acetate, adipate, alginate, citrate, aspartate, benzoate,benzenesulfonate, bisulfate, butyrate, camphorate, camphorsulfonate;digluconate, dihydrobromide, dihydrochloride, dihydroiodide,glycerophosphate, hemisulfate, heptanoate, hexanoate, formate, fumarate,hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate,lactate, maleate, mesitylenesulfonate, methanesulfonate,naphthylenesulfonate, nicotinate, 2-naphthalenesulfonate, oxalate,palmoate, pectinate, persulfate, 3-phenylproprionate, picrate, pivalate,propionate, succinate, tartrate, trichloroacetate, trifluoroacetate,phosphate, glutamate, bicarbonate, para-toluenesulfonate, andundecanoate. Examples of acids which can be employed to formpharmaceutically acceptable addition salts include inorganic acids suchas hydrochloric, hydrobromic, sulfuric, and phosphoric, and organicacids such as oxalic, maleic, succinic, and citric.

Basic addition salts can be prepared during the final isolation andpurification of the compounds by reacting a carboxy group with asuitable base such as the hydroxide, carbonate, or bicarbonate of ametal cation or with ammonia or an organic primary, secondary, ortertiary amine. The cations of pharmaceutically acceptable salts includelithium, sodium, potassium, calcium, magnesium, and aluminum, as well asnontoxic quaternary amine cations such as ammonium, tetramethylammonium,tetraethylammonium, methylamine, dimethylamine, trimethylamine,triethylamine, diethylamine, ethylamine, tributylamine, pyridine,N,N-dimethylaniline, N-methylpiperidine, N-methylmorpholine,dicyclohexylamine, procaine, dibenzylamine, N,N-dibenzylphenethylamine,and N,N′-dibenzylethylenediamine. Other representative organic aminesuseful for the formation of base addition salts include ethylenediamine,ethanolamine, diethanolamine, piperidine, and piperazine.

One embodiment of this disclosure encompasses methods of inhibitingadaptor associated kinase 1 (AAK1), both in vitro and in vivo, whichcomprise contacting AAK1 with a compound of formula I or apharmaceutically acceptable salt thereof.

When it is possible that, for use in therapy, therapeutically effectiveamounts of a compound of formula (I), as well as pharmaceuticallyacceptable salts thereof, may be administered as the raw chemical, it ispossible to present the active ingredient as a pharmaceuticalcomposition. Accordingly, the disclosure further provides pharmaceuticalcompositions, which include therapeutically effective amounts ofcompounds of formula (I) or pharmaceutically acceptable salts thereof,and one or more pharmaceutically acceptable carriers, diluents, orexcipients. Unless otherwise indicated, a “therapeutically effectiveamount” of a compound is an amount sufficient to provide a therapeuticbenefit in the treatment or management of a disease or condition, or todelay or minimize one or more symptoms associated with the disease orcondition. The term “therapeutically effective amount” can encompass anamount that improves overall therapy, reduces or avoids symptoms orcauses of a disease or condition, or enhances the therapeutic efficacyof another therapeutic agent.

The term “therapeutically effective amount,” as used herein, refers toan amount of a compound or compounds sufficient to provide a therapeuticbenefit in the treatment or management of a disease or condition, or todelay or minimize one or more symptoms associated with the disease orcondition. A “therapeutically effective amount” of a compound means anamount of therapeutic agent, alone or in combination with othertherapies, that provides a therapeutic benefit in the treatment ormanagement of the disease or condition. The term “therapeuticallyeffective amount” can encompass an amount that improves overall therapy,reduces or avoids symptoms or causes of a disease or condition, orenhances the therapeutic efficacy of another therapeutic agent. Whenapplied to an individual active ingredient, administered alone, the termrefers to that ingredient alone. When applied to a combination, the termrefers to combined amounts of the active ingredients that result in thetherapeutic effect, whether administered in combination, serially, orsimultaneously. The compounds of formula (I) and pharmaceuticallyacceptable salts thereof, are as described above. The carrier(s),diluent(s), or excipient(s) must be acceptable in the sense of beingcompatible with the other ingredients of the formulation and notdeleterious to the recipient thereof. In accordance with another aspectof the present disclosure there is also provided a process for thepreparation of a pharmaceutical formulation including admixing acompound of formula (I), or a pharmaceutically acceptable salt thereof,with one or more pharmaceutically acceptable carriers, diluents, orexcipients. The term “pharmaceutically acceptable,” as used herein,refers to those compounds, materials, compositions, and/or dosage formswhich are, within the scope of sound medical judgment, suitable for usein contact with the tissues of patients without excessive toxicity,irritation, allergic response, or other problem or complicationcommensurate with a reasonable benefit/risk ratio, and are effective fortheir intended use.

Pharmaceutical formulations may be presented in unit dose formscontaining a predetermined amount of active ingredient per unit dose.Dosage levels of between about 0.01 and about 250 milligram per kilogram(“mg/kg”) body weight per day, preferably between about 0.05 and about100 mg/kg body weight per day of the compounds of the present disclosureare typical in a monotherapy for the prevention and treatment ofdisease. Typically, the pharmaceutical compositions of this disclosurewill be administered from about 1 to about 5 times per day oralternatively, as a continuous infusion. Such administration can be usedas a chronic or acute therapy. The amount of active ingredient that maybe combined with the carrier materials to produce a single dosage formwill vary depending on the condition being treated, the severity of thecondition, the time of administration, the route of administration, therate of excretion of the compound employed, the duration of treatment,and the age, gender, weight, and condition of the patient. Preferredunit dosage formulations are those containing a daily dose or sub-dose,as herein above recited, or an appropriate fraction thereof, of anactive ingredient. Treatment may be initiated with small dosagessubstantially less than the optimum dose of the compound. Thereafter,the dosage is increased by small increments until the optimum effectunder the circumstances is reached. In general, the compound is mostdesirably administered at a concentration level that will generallyafford effective results without causing any harmful or deleterious sideeffects.

When the compositions of this disclosure comprise a combination of acompound of the present disclosure and one or more additionaltherapeutic or prophylactic agent, both the compound and the additionalagent are usually present at dosage levels of between about 10 to 150%,and more preferably between about 10 and 80% of the dosage normallyadministered in a monotherapy regimen.

Compounds of the disclosure may be administered in combination with oneor more additional therapeutic or prophylactic agents. For example, whenused for the treatment of pain, possible additional agents includeimmunosuppressive agents, anti-inflammatory agents, and/or other agentsused in the treatment of pain.

Immunosuppressants suitable for use in the methods and compositions ofthis disclosure include those known in the art. Examples includeaminopterin, azathioprine, cyclosporin A, D-penicillamine, gold salts,hydroxychloroquine, leflunomide, methotrexate, minocycline, rapamycin,sulfasalazine, tacrolimus (FK506), and pharmaceutically acceptable saltsthereof. A particular immunosuppressant is methotrexate.

Additional examples of immunosuppressants include anti-TNF antibodies,such as adalimumab, certolizumab pegol, etanercept, and infliximab.Others include interleukin-1 blockers, such as anakinra. Others includeanti-B cell (CD20) antibodies, such as rituximab. Others include T cellactivation blockers, such as abatacept.

Other immunosuppressants include inosine monophosphate dehydrogenaseinhibitors, such as mycophenolate mofetil (CellCept®) and mycophenolicacid (Myfortic®).

Anti-inflammatory drugs suitable for use in the methods and compositionsof this disclosure include those known in the art. Examples includeglucocorticoids and NSAIDs. Examples of glucocorticoids includealdosterone, beclometasone, betamethasone, cortisone,deoxycorticosterone, dexamethasone, fludrocortisones, hydrocortisone,methylprednisolone, prednisolone, prednisone, triamcinolone, andpharmaceutically acceptable salts thereof.

Examples of NSAID include salicylates (e.g., aspirin, amoxiprin,benorilate, choline magnesium salicylate, diflunisal, faislamine, methylsalicylate, magnesium salicylate, salicyl salicylate, andpharmaceutically acceptable salts thereof), arylalkanoic acids (e.g.,diclofenac, aceclofenac, acemetacin, bromfenac, etodolac, indometacin,nabumetone, sulindac, tolmetin, and pharmaceutically acceptable saltsthereof), arylpropionic acids (e.g., ibuprofen, carprofen, fenbufen,fenoprofen, flurbiprofen, ketoprofen, ketorolac, loxoprofen, naproxen,oxaprozin, tiaprofenic acid, suprofen, and pharmaceutically acceptablesalts thereof), arylanthranilic acids (e.g., meclofenamic acid,mefenamic acid, and pharmaceutically acceptable salts thereof),pyrazolidine derivatives (e.g., azapropazone, metamizole,oxyphenbutazone, phenylbutazone, sulfinprazone, and pharmaceuticallyacceptable salts thereof), oxicams (e.g., lornoxicam, meloxicam,piroxicam, tenoxicam, and pharmaceutically acceptable salts thereof),COX-2 inhibitors (e.g., celecoxib, etoricoxib, lumiracoxib, parecoxib,rofecoxib, valdecoxib, and pharmaceutically acceptable salts thereof),and sulphonanilides (e.g., nimesulide and pharmaceutically acceptablesalts thereof).

Other agents used in the treatment of pain (including but not limited toneuropathic and inflammatory pain) include, but are not limited to,agents such as pregabalin, lidocaine, duloxetine, gabapentin,carbamazepine, capsaicin, and other serotonin/norepinephrine/dopaminereuptake inhibitors, and opiates (such as oxycontin, morphine, andcodeine).

In the treatment of pain caused by a known disease or condition, such asdiabetes, infection (e.g., herpes zoster or HIV infection), or cancer,compounds of the disclosure may be administered in combination with oneor more additional therapeutic or prophylactic agents directed at theunderlying disease or condition. For example, when used to treatdiabetic neuropathy, compounds of the disclosure may be administered incombination with one or more anti-diabetic agents, anti-hyperglycemicagents, hypolipidemic/lipid lowering agents, anti-obesity agents,anti-hypertensive agents and appetite suppressants. Examples ofanti-diabetic agents include biguanides (e.g., metformin, phenformin),glucosidase inhibitors (e.g., acarbose, miglitol), insulins (includinginsulin secretagogues and insulin sensitizers), meglitinides (e.g.,repaglinide), sulfonylureas (e.g., glimepiride, glyburide, gliclazide,chlorpropamide, and glipizide), biguanide/glyburide combinations (e.g.,Glucovance), thiazolidinediones (e.g., troglitazone, rosiglitazone, andpioglitazone), PPAR-alpha agonists, PPAR-gamma agonists, PPARalpha/gamma dual agonists, glycogen phosphorylase inhibitors, inhibitorsof fatty acid binding protein (aP2), glucagon-like peptide-1 (GLP-1) orother agonists of the GLP-1 receptor, dipeptidyl peptidase IV (DPP4)inhibitors, and sodium-glucose co-transporter 2 (SGLT2) inhibitors(e.g., dapagliflozin, canagliflozin, and LX-4211).

Pharmaceutical formulations may be adapted for administration by anyappropriate route, for example by the oral (including buccal orsublingual), rectal, nasal, topical (including buccal, sublingual, ortransdermal), vaginal, or parenteral (including subcutaneous,intracutaneous, intramuscular, intra-articular, intrasynovial,intrasternal, intrathecal, intralesional, intravenous, or intradermalinjections or infusions) route. Such formulations may be prepared by anymethod known in the art of pharmacy, for example by bringing intoassociation the active ingredient with the carriers) or excipient(s).Oral administration or administration by injection are preferred.

Pharmaceutical formulations adapted for oral administration may bepresented as discrete units such as capsules or tablets; powders orgranules; solutions or suspensions in aqueous or non-aqueous liquids;edible foams or whips; or oil-in-water liquid emulsions or water-in-oilemulsions.

For instance, for oral administration in the form of a tablet orcapsule, the active drug component can be combined with an oral,non-toxic pharmaceutically acceptable inert carrier such as ethanol,glycerol, water, and the like. Powders are prepared by comminuting thecompound to a suitable fine size and mixing with a similarly comminutedpharmaceutical carrier such as an edible carbohydrate, as, for example,starch or mannitol. Flavoring, preservative, dispersing, and coloringagent can also be present.

Capsules are made by preparing a powder mixture, as described above, andfilling formed gelatin sheaths. Glidants and lubricants such ascolloidal silica, talc, magnesium stearate, calcium stearate, or solidpolyethylene glycol can be added to the powder mixture before thefilling operation. A disintegrating or solubilizing agent such asagar-agar, calcium carbonate, or sodium carbonate can also be added toimprove the availability of the medicament when the capsule is ingested.

Moreover, when desired or necessary, suitable binders, lubricants,disintegrating agents, and coloring agents can also be incorporated intothe mixture. Suitable binders include starch, gelatin, natural sugarssuch as glucose or beta-lactose, corn sweeteners, natural and syntheticgums such as acacia, tragacanth or sodium alginate,carboxymethylcellulose, polyethylene glycol, and the like. Lubricantsused in these dosage forms include sodium oleate, sodium chloride, andthe like. Disintegrators include, without limitation, starch, methylcellulose, agar, betonite, xanthan gum, and the like. Tablets areformulated, for example, by preparing a powder mixture, granulating orslugging, adding a lubricant and disintegrant, and pressing intotablets. A powder mixture is prepared by mixing the compound, suitablecomminuted, with a diluent or base as described above, and optionally,with a binder such as carboxymethylcellulose, an aliginate, gelating, orpolyvinyl pyrrolidone, a solution retardant such as paraffin, aresorption accelerator such as a quaternary salt and/or and absorptionagent such as betonite, kaolin, or dicalcium phosphate. The powdermixture can be granulated by wetting with a binder such as syrup, starchpaste, acadia mucilage, or solutions of cellulosic or polymericmaterials and forcing through a screen. As an alternative togranulating, the powder mixture can be run through the tablet machineand the result is imperfectly formed slugs broken into granules. Thegranules can be lubricated to prevent sticking to the tablet formingdies by means of the addition of stearic acid, a stearate salt, talc, ormineral oil. The lubricated mixture is then compressed into tablets. Thecompounds of the present disclosure can also be combined with a freeflowing inert carrier and compressed into tablets directly without goingthrough the granulating or slugging steps. A clear or opaque protectivecoating consisting of a sealing coat of shellac, a coating of sugar orpolymeric material, and a polish coating of wax can be provided.Dyestuffs can be added to these coatings to distinguish different unitdosages.

Oral fluids such as solution, syrups, and elixirs can be prepared indosage unit form so that a given quantity contains a predeterminedamount of the compound. Syrups can be prepared by dissolving thecompound in a suitably flavored aqueous solution, while elixirs areprepared through the use of a non-toxic vehicle. Solubilizers andemulsifiers such as ethoxylated isostearyl alcohols and polyoxyethylenesorbitol ethers, preservatives, flavor additive such as peppermint oilor natural sweeteners, or saccharin or other artificial sweeteners, andthe like can also be added.

Where appropriate, dosage unit formulations for oral administration canbe microencapsulated. The formulation can also be prepared to prolong orsustain the release as for example by coating or embedding particulatematerial in polymers, wax, or the like.

The compounds of formula (I), and pharmaceutically acceptable saltsthereof, can also be administered in the form of liposome deliverysystems, such as small unilamellar vesicles, large unilamellar vesicles,and multilamellar vesicles. Liposomes can be formed from a variety ofphopholipids, such as cholesterol, stearylamine, or phophatidylcholines.

The compounds of formula (I) and pharmaceutically acceptable saltsthereof may also be delivered by the use of monoclonal antibodies asindividual carriers to which the compound molecules are coupled. Thecompounds may also be coupled with soluble polymers as targetable drugcarriers. Such polymers can include polyvinylpyrrolidone, pyrancopolymer, polyhydroxypropylmethacrylamidephenol,polyhydroxyethylaspartamidephenol, or polyethyleneoxidepolylysinesubstituted with palitoyl residues. Furthermore, the compounds may becoupled to a class of biodegradable polymers useful in achievingcontrolled release of a drug, for example, polylactic acid, polepsiloncaprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals,polydihydropyrans, polycyanoacrylates, and cross-linked or amphipathicblock copolymers of hydrogels.

Pharmaceutical formulations adapted for transdermal administration maybe presented as discrete patches intended to remain in intimate contactwith the epidermis of the recipient for a prolonged period of time. Forexample, the active ingredient may be delivered from the patch byiontophoresis as generally described in Pharmaceutical Research 1986,3(6), 318.

Pharmaceutical formulations adapted for topical administration may beformulated as ointments, creams, suspensions, lotions, powders,solutions, pastes, gels, sprays, aerosols, or oils.

Pharmaceutical formulations adapted for rectal administration may bepresented as suppositories or as enemas.

Pharmaceutical formulations adapted for nasal administration wherein thecarrier is a solid include a course powder having a particle size forexample in the range 20 to 500 microns which is administered in themanner in which snuff is taken, i.e., by rapid inhalation through thenasal passage from a container of the powder held close up to the nose.Suitable formulations wherein the carrier is a liquid, foradministration as a nasal spray or nasal drops, include aqueous or oilsolutions of the active ingredient.

Pharmaceutical formulations adapted for administration by inhalationinclude fine particle dusts or mists, which may be generated by means ofvarious types of metered, dose pressurized aerosols, nebulizers, orinsufflators.

Pharmaceutical formulations adapted for vaginal administration may bepresented as pessaries, tampons, creams, gels, pastes, foams, or sprayformulations.

Pharmaceutical formulations adapted for parenteral administrationinclude aqueous and non-aqueous sterile injection solutions which maycontain anti-oxidants, buffers, bacteriostats, and soutes which renderthe formulation isotonic with the blood of the intended recipient; andaqueous and non-aqueous sterile suspensions which may include suspendingagents and thickening agents. The formulations may be presented inunit-dose or multi-dose containers, for example sealed ampoules andvials, and may be stored in a freeze-dried (lyophilized) conditionrequiring only the addition of the sterile liquid carrier, for examplewater for injections, immediately prior to use. Extemporaneous injectionsolutions and suspensions may be prepared from sterile powders,granules, and tablets.

It should be understood that in addition to the ingredients particularlymentioned above, the formulations may include other agents conventionalin the art having regard to the type of formulation in question, forexample those suitable for oral administration may include flavoringagents.

The term “patient” includes both human and other mammals. Unlessotherwise indicated, the terms “manage,” “managing”, and “management”encompass preventing the recurrence of the specified disease or disorderin a patient who has already suffered from the disease or disorder,and/or lengthening the time that a patient who has suffered from thedisease or disorder remains in remission. The terms encompass modulatingthe threshold, development and/or duration of the disease or disorder,or changing the way that a patient responds to the disease or disorder.

The term “treating” refers to: (i) preventing a disease, disorder orcondition from occurring in a patient that may be predisposed to thedisease, disorder, and/or condition but has not yet been diagnosed ashaving it; (ii) inhibiting the disease, disorder, or condition, i.e.,arresting its development; and (iii) relieving the disease, disorder, orcondition, i.e., causing regression of the disease, disorder, and/orcondition.

This disclosure is intended to encompass compounds having formula (I)when prepared by synthetic processes or by metabolic processes includingthose occurring in the human or animal body (in vivo) or processesoccurring in vitro.

The abbreviations used in the present application, includingparticularly in the illustrative schemes and examples which follow, arewell-known to those skilled in the art. Some of the abbreviations usedare as follows: RT or rt or r.t. for room temperature; t_(R) forretention time; min or mins for minutes; h or hr or hrs for hours; MeODfor CD₃OD; THF for tetrahydrofuran; ACN or MeCN for acetonitrile; DCMfor dichloromethane; MeOH for methanol; EtOH for ethanol; t-BuOH fort-butanol, DMSO for dimethylsulfoxide; DMF for N,N-dimethylformamide;EtOAc for ethyl acetate; BOC or Boc for tert-butoxycarbonyl; Me formethyl; Et for ethyl; Cyc-Pr for cyclopropyl; phth for phthaloyl; Ac foracetyl; Ph for phenyl; DPPA for diphenylphosphoryl azide; Et₃N or TEAfor triethylamine; n-BuLi for n-butyllithium; TFA for trifluoroaceticacid; NBS for N-bromosuccinimide; NCS for N-chlorosuccinimide; NIS forN-iodosuccinimide; DEA for diethylamine; LDA for lithiumdiisopropylamide; LAH for lithium aluminum hydride; DBU for1,8-diazabicycloundec-7-ene; DMAP for N,N-dimethylaminopyridine; DPPF ordppf for 1,1′-bis(diphenylphosphanyl) ferrocene; LDA for lithiumdiisopropylamide; NBS for N-bromosuccinimide; TMS for trimethylsilyl;TBAF for tetrabutylammonium fluoride; NCS for N-chlorosuccinimide; TFAfor trifluoracetic acid; NIS for N-iodosuccinimide; and Ac for acetyl.

EXAMPLES

The present disclosure will now be described in connection with certainembodiments which are not intended to limit its scope. On the contrary,the present disclosure covers all alternatives, modifications, andequivalents as can be included within the scope of the claims. Thus, thefollowing examples, which include specific embodiments, will illustrateone practice of the present disclosure, it being understood that theexamples are for the purposes of illustration of certain embodiments andare presented to provide what is believed to be the most useful andreadily understood description of its procedures and conceptual aspects.

The compounds of the present disclosure may be prepared using thereactions and techniques described in this section as well as othersynthetic methods known to those of ordinary skill in the art. Thereactions are performed in solvents appropriate to the reagents andmaterials employed and suitable for the transformation being affected.Also, in the description of the synthetic methods described below, it isto be understood that all proposed reaction conditions, including choiceof solvents, reaction temperature, duration of the experiment and workupprocedures, are chosen to be the conditions standard for that reaction,which should be readily recognized by one skilled in the art. It isunderstood by one skilled in the art of organic synthesis that thefunctionality present on various portions of the molecule must becompatible with the reagents and reactions proposed. Such restrictionsto the substituents which are compatible with the reaction conditionswill be readily apparent to one skilled in the art and alternate methodsmust then be used.

Compounds of formula 6, wherein R¹ and R² are H, alkyl, cycloalkyl oralkenyl, are prepared by the methods outlined in Scheme 1. Theappropriate sodium phenolate can be alkylated with a suitablysubstituted propargyl halide at ambient temperature to provide thedesired propargyl ether 2. Wittig reaction of the aldehyde function in 2with appropriate Wittig reagent can result in the formation of thedesired olefin as mixture of E, Z mixture with the E-isomer being themajor product. The α,β-unsaturated aldehyde isomeric mixture 3 thusobtained can be converted to hydrazone derivative 4 by reaction with1,1-dimethylhydrazine in a solvent such as dichloromethane in presenceof a dehydrating agent such as MgSO₄. The crude hydrazone 4 thusobtained can be subjected to an intramolecular [4+2] cycloadditionreaction in presence of a radical scavenger such as2,6-di-tert-butyl-4-methylphenol in a solvent such as mesitylene (Dolle,R. E. et. al. Tetrahedron Lett. 1988, 29, 6349-6352) to provide thecyclization product 5. The bromide in 5 can be replaced by reaction withan alcohol in a palladium catalyzed coupling reaction using reactionconditions familiar to those skilled in the art following proceduressuch as those described by Gowrisankar, et. al. J. Am. Chem. Soc. 2010,132, 11592-11598. For the purpose of preparing ethers represented by 6from bromides 5, any other functional groups in R³OH capable ofinterfering in Pd coupling reaction can be protected with an appropriateprotecting group reagent as described in Protective Groups in OrganicSynthesis (Greene, Wuts; 3^(rd) ed., 1999, John Wiley & Sons, Inc.).These protecting groups can subsequently be unmasked by the methodsdescribed in the same reference above. For example, the amino group canbe protected as a phthalimido derivative which after Pd couplingreaction to provide 7 can be unmasked by treatment with hydrazine inethanol as shown in Scheme 1 to provide 8.

Compounds of formula 17, wherein R¹ is H, alkyl, alkenyl, R⁵ is H, halo,CN and R³ is H, alkyl, cycloalkyl, are prepared by the methods outlinedin Scheme 2. 4-Bromopyridine or 4-chloropyridine hydrochloride salt canbe subjected to base mediated formylation with a base such as lithiumdiisopropylamide to give the corresponding 3-formyl pyridine asdescribed by Knutsen, L. et. al. (Bioorganic & Medicinal ChemistryLetters, 2007, 17, 662-667). The aldehyde 9, so obtained can besubjected to Suzuki cross coupling reaction with an appropriate couplingpartner such as fluoroboronic acid 11, under standard Suzuki conditionsemploying a base such as cesium carbonate and a catalyst such asPd(PPh₃)₄ as described by Zhang, Lei et. al. (Journal of MedicinalChemistry, 2011, 54, 1724-1739). The biaryl aldehyde 10, can then bereduced to the corresponding primary alcohol 12 (R¹═H) with a standardreducing agent such as sodium borohydride. To form the secondaryalcohols 12 (R¹=alkyl, cycloalkyl or alkenyl), the aldehyde 10, can betreated with an appropriate Grignard reagent in a solvent such asanhydrous tetrahydrofuran at low temperature (previously described byItoh, Toshiyuki et. al. Chemistry-A European Journal, 2006, 12,9228-9237 and Zhang, et. al. Tetrahedron Lett., 2010, 51, 3927-3930).The primary or secondary alcohols 12, upon treatment with a hydridesource such as sodium hydride in a solvent such as THF under inertatmosphere can afford the constrained halo-substituted core, 13. Amongthe compounds represented by formula 13, the alkenyl substituted(R¹=vinyl), compound can be hydrogenated using standard hydrogenationconditions such as treatment with palladium on carbon under a hydrogenatmosphere to provide the corresponding alkyl substituted analogues.Compounds of formula 13 can then be subjected to palladium catalyzedether synthesis including reaction conditions familiar to those skilledin the art following procedures such as those described by Gowrisankar,et. al. (J. Am. Chem. Soc. 2010, 132, 11592-11598). The reactions can beperformed using appropriately protected, optically pure (S) or(R)-aminoalcohols to afford optically pure ethers 14. Compounds offormula 15 wherein R⁵ is halo can be prepared by treatment of 14 with ahalogenating agent such as N-bromosuccinamide, N-chlorosuccinamide orN-iodosuccinamide as the case may be. Compound of formula 16 wherein R⁵is cyano can be prepared from the corresponding halo compound via coppercatalyzed coupling reactions, reaction conditions familiar to thoseskilled in the art (J. E. Callen, Organic syntheses, CV 3, 1955, 212).Alternatively, a cyano group can be introduced with zinc cyanide viastandard Negishi coupling conditions in the presence of a catalyst suchas Pd(PPh3)4, Pd2(dba)₃, or PdCl2(PPh3)2, with or without a ligand suchas DPPF in a solvent such as toluene, dichloroethane, THF, DMF,methanol, ethanol, water or a combination thereof at temperaturesranging from 20° C. to 150° C. For the purpose of preparing ethersrepresented by 14 from chlorides 13, or cyanides represented by 16 fromhaldies 15, any other functional groups in R³OH capable of interferingin Cu or Pd coupling reactions can be protected with an appropriateprotecting group reagent as described in Protective Groups in OrganicSynthesis (Greene, Wuts; 3rd ed., 1999, John Wiley & Sons, Inc.). Theseprotecting groups can subsequently be unmasked by the methods describedin the same reference above. Diastereomeric mixtures so obtained couldbe resolved using preparative chiral HPLC or preparative chiral SFCtechniques.

Compounds of formula 23 are prepared by the methods outlined in Scheme3. 4-Chloropyridine pyridine 3-carboxylic acid 17 (where R⁶═H or alkyl)can be converted to the corresponding ester 18 using methods asdescribed in Protective Groups in Organic Synthesis (Greene, Wuts;3^(rd) ed., 1999, John Wiley & Sons, Inc.). The ester can then besubjected to Suzuki cross coupling reaction with an appropriate couplingpartner such as fluoroboronic acid 11, under standard Suzuki conditionsemploying a base such as cesium carbonate and a catalyst such asPd(PPh₃)₄ as described by Zhang, Lei et. al. (Journal of MedicinalChemistry, 2011, 54, 1724-1739) for compounds represented by formula 19.The biaryl ester 19 can be subjected to hydrolysis to yieldcorresponding carboxylic acid 20 under standard saponificationconditions using a base such as sodium hydroxide or lithium hydroxide ina solvent such as methanol, water, THF, or a combination thereof. Theacid can then be heated under basic conditions to yield lactone 21. Thelactone can be subjected to palladium catalyzed ether synthesis usingreaction conditions familiar to those skilled in the art followingprocedures such as those described by Gowrisankar, et. al. (J. Am. Chem.Soc. 2010, 132, 11592-11598). The reactions can be performed usingappropriately protected, optically pure (S) or (R)-aminoalcohols toafford optically pure ethers. For the purpose of preparing ethersrepresented by 22 from halides 21, any other functional groups in R³OHcapable of interfering in Pd coupling reactions can be protected with anappropriate protecting group reagent as described in Protective Groupsin Organic Synthesis (Greene, Wuts; 3rd ed., 1999, John Wiley & Sons,Inc.). Compounds of formula 22 where in R⁵=halo can be prepared byhalogenation of the corresponding ether using a halogenating agent suchas N-chlorosuccinamide. If necessary, the ether analogues can besubjected to deprotection of the side chain amino group usingappropriate conditions as described in Protective Groups in OrganicSynthesis (Greene, Wuts; 3^(rd) ed., 1999, John Wiley & Sons, Inc.) toyield compounds of formula 23.

Compounds of formula 32 and 33, wherein R⁶ is NH₂ or NHAc, are preparedby the methods outlined in Scheme 4. The synthesis can begin withCurtius rearrangement of 4-chloropyridine-2-carboxylic acid 24 to yieldN-Boc-2-amino-4-chloropyridine 25 as described Leslie et. al.(Australian Journal of Chemistry, 1982, 35, 2025-2034). Directedortho-metallation followed by treatment with dimethylformamide canfurnish the pyridine aldehyde derivative 26 using methods such as thosedescribed by Charles et. al. (J. Med. Chem., 2010, 53, 3330-3348). Thealdehyde can then be subjected to Suzuki cross coupling reaction with anappropriate coupling partner such as fluoroboronic acid 11, understandard Suzuki conditions employing a base such as cesium carbonate anda catalyst such as Pd(PPh₃)₄ as described by Zhang, Lei et. al. (Journalof Medicinal Chemistry, 2011, 54, 1724-1739) to give 27. Removal of theprotecting group on the amine using appropriate conditions as describedin Protective Groups in Organic Synthesis (Greene, Wuts; 3^(rd) ed.,1999, John Wiley & Sons, Inc.) followed by reduction of the aldehyde 28mediated by an agent such as sodium borohydride (Eisai R&D ManagementCo., Ltd. Patent: EP1782811 A1, 2007) can provide alcohol 29. To formthe secondary alcohols 29 (R¹=alkyl), the aldehyde 28, can be treatedwith an appropriate Grignard reagent in a solvent such as anhydroustetrahydrofuran at low temperature (previously described by Itoh,Toshiyuki et. al. Chemistry-A European Journal, 2006, 12, 9228-9237 andZhang, et. al. Tetrahedron Lett., 2010, 51, 3927-3930). Cyclizationmediated by a base such as sodium hydride can lead to intermediate 30.The base catalyzed acetylation with acetyl chloride in a solvent such asdichloromethane with a base such as pyridine can provide 31. The arylchloride 31 can then be subjected to a palladium catalyzed ethersynthesis using reaction conditions familiar to those skilled in the artfollowing procedures such as those described by Gowrisankar, et al. (J.Am. Chem. Soc. 2010, 132, 11592-11598) to provide the corresponding arylether. For the purpose of preparing ethers represented by 32 fromhalides 31, any other functional groups in R³OH capable of interferingin Pd coupling reactions can be protected with an appropriate protectinggroup reagent as described in Protective Groups in Organic Synthesis(Greene, Wuts; 3rd ed., 1999, John Wiley & Sons, Inc.). Removal of theprotecting group can be achieved using appropriate conditions asdescribed in the same reference to afford compounds of formula 32wherein R⁶ is NHAc. The N-acetyl group can be removed by hydrolysisusing a base such as potassium hydroxide to provide compounds of formula33 wherein R⁶ is NH₂.

Compounds of formula 35, wherein R⁵ is halo are prepared by the methodsoutlined in Scheme 5. The ether analogues represented by 34 can beprepared as in Scheme 2 and treated with a halogenating agent such asN-halosuccinamide to install a halogen at R⁵. Deprotection of the sidechain amino group using appropriate conditions as described inProtective Groups in Organic Synthesis (Greene, Wuts; 3^(rd) ed., 1999,John Wiley & Sons, Inc.) can yield compounds represented by formula 33wherein R⁵ is halo.

Compounds of formula 47 are prepared by the methods outlined in Scheme6. 4-chloropyridin-2-amine 36 can be treated with brominating agent suchas N-bromosuccinamide to give bromo-amino pyridine 37. The basecatalyzed acetylation of 37 with acetyl chloride in a solvent such asdichloromethane with a base such as pyridine can give rise to acylpyridine 38. Compound 38 can be subjected to Suzuki cross couplingreaction with vinyl boronic anhydride, under standard Suzuki conditionsemploying a base such as cesium carbonate and a catalyst such asPd(PPh₃)₄ as described by Zhang, Lei et. al. (Journal of MedicinalChemistry, 2011, 54, 1724-1739) to install the vinyl group. Vinylpyridine 39 can be subjected to oxidation with oxidizing agent such asosmium tetroxide and sodium periodate in solvents such as dioxane andwater to give aldehyde 40. The aldehyde 40, so obtained can be subjectedto Suzuki cross coupling reaction with an appropriate coupling partnersuch as fluoroboronic acid 41, under standard Suzuki conditionsemploying a base such as cesium carbonate and a catalyst such asPd(PPh₃)₄ as described by Zhang, Lei et. al. (Journal of MedicinalChemistry, 2011, 54, 1724-1739). The biaryl aldehyde 42, can then bereduced to the corresponding primary alcohol 43 (R¹═H) with a standardreducing agent such as sodium borohydride. To form the secondary alcohol43 (R¹=alkyl, cycloalkyl, alkenyl), the aldehyde 42, can be treated withthe appropriate Grignard reagent in a solvent such as anhydroustetrahydrofuran at low temperature (previously described by Itoh,Toshiyuki et. al. Chemistry-A European Journal, 2006, 12, 9228-9237 andZhang, et. al. Tetrahedron Lett., 2010, 51, 3927-3930). Compounds 43,upon treatment with a base such as sodium hydride at ambient temperatureor with base such as potassium carbonate under heating conditions, in asolvent such as THF under inert atmosphere can afford the constrainedchloro-substituted core 44. Compound of formula 44 where in R=Me can beprepared by methylation of corresponding core 44 (R═COOH) using basesuch as sodium hydride and alkylating agent such as methyl iodide insolvent such as THF at low temperature. Compounds of formula 44 where inR═COcyc-Pr, CO(OCH₃) can be prepared by deacylation of 44 (R═COCH₃) withreagent such as potassium hydroxide in solvents such as water andmethanol, followed by acylation with corresponding acid chlorides in thepresence of base such as pyridine based on the protection anddeprotection procedures described in Protective Groups in OrganicSynthesis (Greene, Wuts; 3^(rd) ed., 1999, John Wiley & Sons, Inc.).Compounds of formula 44 can then be subjected to palladium catalyzedether synthesis including reaction conditions familiar to those skilledin the art following procedures such as m those described byGowrisankar, et. al. (J. Am. Chem. Soc. 2010, 132, 11592-11598). Thereactions can be performed, for example, using appropriately protectedracemic or optically pure (S) or (R)-aminoalcohols to afford racemic oroptically pure ethers respectively. For the purpose of preparing ethersrepresented by 45 from halides 44, any other functional groups in R³OHcapable of interfering in Pd coupling reactions, such as the amino groupof an aminoalcohol, can be protected with an appropriate protectinggroup reagent as described in Protective Groups in Organic Synthesis(Greene, Wuts; 3rd ed., 1999, John Wiley & Sons, Inc.). Removal of theprotecting group can be achieved using appropriate conditions asdescribed in the same reference to afford compounds of formula 47.Compound of formula 46 where in R⁵=halo can be prepared by halogenationof the corresponding ether (R⁵═H) using halogenating agent such asN-chlorosuccinamide. The ether analogues represented by compoundscompounds 46 obtained via palladium catalyzed reactions, can besubjected to deprotection of R³ if necessary using appropriateconditions as described in Protective Groups in Organic Synthesis(Greene, Wuts; 3^(rd) ed., 1999, John Wiley & Sons, Inc.) to yieldcompounds represented by formula 47. The diastereomeric mixtures soobtained could be resolved using preparative chiral HPLC or preparativechiral SFC techniques.

Compounds of formula 53 are prepared by the methods outlined in Scheme7. Substituted 4-bromopyridine or 4-chloropyridine can be subjected tobase mediated carboxylation with a base such as lithium diisopropylamideand dry ice to give the corresponding pyridine-3-carboxylic acid 48. Theacid can be esterified using standard conditions known to those skilledin the art, such as treatment with a base such as DBU and an alkylatingagent such as methyl iodide to give esters represented by the formula49. The halopyrine, 49, can then be subjected to Suzuki cross couplingreaction with an appropriate coupling partner such as fluoroboronic acid11, under standard Suzuki conditions employing a base such as cesiumcarbonate and a catalyst such as Pd(PPh₃)₄ as described by Zhang, Leiet. al. (Journal of Medicinal Chemistry, 2011, 54, 1724-1739) forcompounds represented by formula 50. The ester can be converted to thecorresponding alcohol represented by formula 51 by treatment with areducing agent such as LAH. The alcohol, upon treatment with a hydridesource such as sodium hydride in a solvent such as THF under inertatmosphere can afford the constrained halo-substituted core, 52.Compounds of formula 52 can then be subjected to palladium catalyzedether synthesis including reaction conditions familiar to those skilledin the art following procedures such as those described by Gowrisankar,et. al. (J. Am. Chem. Soc. 2010, 132, 11592-11598). For the purpose ofpreparing ethers represented by 53 from chlorides 52 any otherfunctional groups in R³OH capable of interfering in Pd couplingreactions can be protected with an appropriate protecting group reagentas described in Protective Groups in Organic Synthesis (Greene, Wuts;3rd ed., 1999, John Wiley & Sons, Inc.). These protecting groups cansubsequently be unmasked by the methods described in the same referenceabove.

Various analogues synthesized using Schemes 1-7 are listed in Table 1a.AAK1 functional (AAK1 IC₅₀ (nM)) and cellular (cell IC₅₀ (nM)) potencyfor select compounds are shown in Table 1b and are listed as IC₅₀ rangeswhere: a=<1 nM; b=1-10 nM; c=10-100 nM; d=100-1000 nM.

TABLE 1a (I)

Stereo- Ex chem R¹ R² R⁴ R⁵ R⁶ R⁷ R⁸ R³ 1 R H H H H H H H

2 R H H H H H H H

3 R H H H H H H H

4 S H H H H H H H

5 S H H H H H H H

6 diastereo- mers Me H H H H H H

6a Dia-1 Me H H H H H H

6b Dia-2 H Me H H H H H

7a Dia-1 Me H H H H H H

7b Dia-2 H Me H H H H H

8 diastereo- mers Cyc-Pr H H H H H H

8a Dia-1 Cyc-Pr H H H H H H

8b Dia-2 H Cyc-Pr H H H H H

9 diastereo- mers Cyc-Pr H H H H H H

9a Dia-1 Cyc-Pr H H H H H H

9b Dia-2 H Cyc-Pr H H H H H

10 diastereo- mers Et H H H H H H

10a Dia-1 Et H H H H H H

10b Dia-2 H Et H H H H H

11 S ═O H H H H H

12 S H H H H NHAc H H

13 S H H H H NH₂ H H

14 S H H H Br H H H

15 S Me H H H NH2 H H

16 S H H H H H H F

17 Racemate H H H H H H H

18 S H H NHAc H H H H

19 S

H H H H H

20 S CH2OH CH2Cl H H H H H

21 S Me H H Br H H H

22 S Me H H CN H H H

23 S H H H CN H H H

24 diastereo- mers Me H H H H H H

25 S ═O H Br H H H

26 diastereo- mers Me H H H H H H

27 diastereo- mers CF3 H H Cl H H H

27a Dia-1 CF3 H H Cl H H H

27b Dia-2 CF3 H H Cl H H H

28 diastereo- mers CF3 H H Br H H H

29 diastereo- mers Me H NH2 H H H H

30 diastereo- mers Me H NHAc H H H H

31a Dia-1 H Me H I H H H

31b Dia-2 Me H H I H H H

32 S H H NHAc Cl H H H

33 S H H NH₂ H H H H

34 S ═O H H Me H H

35 S H H NHAc H H Me H

36 Racemate H H NHAc H H H H

37 S H H NHAc H H OMe H

38 S H H NHAc H H CHF2 H

39 S H H Me H H H H

40 R H H NHAc H H H H

41 S H H NHAc H H F H

42 S H H

H H H H

43 S H H

H H H H

44 Racemate H H NHAc H H H H

TABLE 1b AAK1 IC₅₀ cell IC₅₀ Ex (M + H)⁺ (nM) (nM)  1 299.2 20  2 333.2d  3 271.1 d  4 271.1 c  5 299.2   3.3 8.4  6 313.2 b  6a 313.2 27 25 6b 313.2   9.1 4.3  7a 313.2 81 >300  7b 313.2 c  8 339.2 c c  8a 339.2d  8b 339.2 c c  9 339.2 d  9a 339.2 d >300  9b 339.2 d >300 10 327.2 cc 10a 327.2 c c 10b 327.2 c c 11 313.2 22 38 12 356.2 c c 13 314.2 b b14 377.0 b b 15 328.2 b b 16 317.0 b b 17 339.1 c c 18 356.2 b c 19341.2 d 20 377.2 c 21 391.0 b a 22 338.2 b a 23 324.2 b 24 339.2 c c 25391.0 b 26 331.2 b c 27 401.2 b b 27a 401.2 b 27b 401.2 b b 28 445.2 b b29 328.2 c 30 370.2 c 31a 439.0 b 31b 439.0 b 32 390.2 66 >100 33 314.2c c 34 327.2 c 35 370.2 a a 36 396.2 c b 37 386.2 c b 38 406.2 a b 39312.5 d 40 356.2 b 41 372.2   0.3 2.1 42 382.3   0.5 2.1 43 372.2 b b 44370.4 b cIn the following examples, proton NMR spectra were recorded on either aBruker 400 or 500 MHz NMR spectrometer. Chemical shifts are reported in8 values relative to tetramethylsilane. Liquid chromatography (LC)/massspectra were run on a Shimadzu LC coupled to a Waters Micromass ZQ. HPLCretention times were obtained using at least one of the followingmethods:

LC-MS Methods:

Method A: Phenomenex C18 2×50 mm (3 μm), A=95% H₂O/5% MeCN, B=95%MeCN/5% H₂O, Modifier 10 mM NH₄OAc, 0.00 min=0% B, 4 min=100% B 5min=100% B, Flow rate=0.8 mL/minMethod B: Phenomenex C18 2×50 mm (3 μm), A=95% H₂O/5% ACN, B=95% MeCN/5%H₂O, Modifier 10 mM NH₄OAc, 0.00 min=30% B, 4 min=100% B 5 min=100% B,Flow rate=0.8 mL/minLC/MS Method C=Column: PUROSPHER@star RP-18 (4×55 mm), 3 μm; Buffer: 20mMNH₄OAC IN WATER; Mphase A: Buffer+ACN(90+10); Mphase B:Buffer+MeCN(10+90); Flow: 2.5 ml/min)LC/MS Method D=Column: ZORBAX SB C18 (46×50 mm), 5 μm; Positive modeMphase A: 10% MeOH—90% H2O—0.1% TFA; Mphase B: 90% MeOH—10% H₂O—0.1%TFA; Flow: 5 ml/min)LC/MS Method E=Column—Ascentis Express C8 (5×2.1 mm), 2.7 μm; Mphase A:2% MeCN—98% H₂O—10 mM NH₄COOH; Mphase B: 98% ACN—2% H₂O—10 mM NH₄COOH;Flow: 1 mL/min)LC/MS Method F=Column—ACQUITY UPLC BEH C18 (2.1×50 mm), 1.7 μm; MphaseA:0.1% TFA in water; Mphase B: 1% TFA in ACN; Flow: 1 mL/min)LC/MS Method G=Column—ACQUITY UPLC BEH C18 (2.1×50 mm), 1.7 μm; MphaseA:5 mM NH4OAc:ACN (95:5); Mphase B: 5 mM NH4OAc:ACN (5:95) Flow: 1mL/min)LC/MS Method H=Column: Xbridge BEH C18 (50×2.1 mm) 2.5 μm, Mobile phaseA-1% HCOOH in H₂O; Mobile Phase B: ACN, Flow rate 1 mL/min): t_(R)=1.55minLC/MS Method I=Column—ACE Excel 2 C18 (50×3.0)mm-2 μm; Mphase A: 2%MeCN—98% H₂O—10 mM NH4COOH; Mphase B: 98% ACN—2% H₂O—10 mM NH₄COOH;Flow: 1.2 mL/min):LC/MS Method J=Column: Xbridge C18 (50×2.1 mm) 2.5 um, Mobile phase A-10mM Ammonium hydrogen carbonate, Mobile Phase B: ACN, Flow rate 1 mL/minLC/MS Method K=Column: Kinetex C18 (50×2.1 mm-2.6 μm), Mobile phase A-2%ACN—98% H₂O-10 mM Ammonium formate, Mobile Phase B: 98% ACN—2% H₂O-10 mMAmmonium formate, Flow rate 1 mL/min

Preparative HPLC Methods:

Method A: Waters Atlantis 30×100 mm, A=90% H₂O/10% MeOH, B=90% MeOH/10%H₂O, Modifier 0.1% TFA, 0.00 min=10% B, 12 min=100% B, 15.0 min=100% B,Flow rate=40 mL/min.Method B: Waters Atlantis OBD 30×100 mm S5, A=90% H₂O/10% MeOH, B=90%MeOH/10% H₂O, Modifier 0.1% TFA, 0.00 min=10% B, 15 min=100% B, 18.0min=100% B, Flow rate=40 mL/min.Method C: Waters Atlantis 30×100 mm, A=90% H₂O/10% MeOH, B=90% MeOH/10%H₂O, Modifier 0.1% TFA, 0.00 min=10% B, 15 min=100% B, Flow rate=40mL/min.

Chiral HPLC Methods:

Method A: CHIRALCEL OJH (250×4.6) mm 5 micron

Mob. phase: 0.2% DEA in n-hexane:ethanol (80:20)

Method B: CHIRALPAK AD-H (250×4.6) mm 5 micron

Mob. Phase A: 0.2% DEA in n-hexane (70) B: ethanol (30)

Method C: CHIRALPAK-ASH (250×4.6) mm 5 micron

Mob. Phase A: 0.2% DEA in n-hexane:ethanol (90:10)

Analytical HPLC Methods:

Method A: Waters analytical C18 sunfire column (4.6×150 mm, 3.5 μm);mobile phase:Buffer: 0.05% TFA in H₂O pH=2.5 adjusted with ammoniaA=buffer and acetonitrile (95:5), B=acetonitrile and buffer (95:5); 0-15min, 0% B→50% B; 15-18 min, 50% B→100% B; 18-23 min, 100% B; flow rate=1mL/min; λ=254 nm and 220 nm; run time=28 min.Method B: Waters analytical phenyl xbridge column (4.6×150 mm, 3.5 μm),mobile phase:Buffer: 0.05% TFA in H₂O pH=2.5 adjusted with ammoniaA=buffer and acetonitrile (95:5), B=acetonitrile and buffer (95:5); 0-15min, 0% B→50% B; 15-18 min, 50% B→100% B; 18-23 min, 100% B; flow rate=1mL/min; λ=254 nm and 220 nm; run time=28 min.

Example 1(R)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine

Part A. 4-bromo-2-(prop-2-ynyloxy)benzaldehyde

Conversion of 4-bromo-2-hydroxybenzaldehyde to its sodium salt wascarried out as follows: A solution of 4-bromo-2-hydroxybenzaldehyde (3.0g, 24.9 mmol) in MeOH (−150 mL) was treated with 1N aq. NaOH (15.7 mL,1.05 equiv). The resulting pale yellow solution was concentrated underreduced pressure. EtOH (30 mL) was added to the residue and the solutionwas concentrated under reduced pressure. This was repeated with EtOH (30mL) and then with heptane (50 mL). The resulting yellow, powdery sodiumsalt was dissolved in DMF (60 mL) with stirring and to it was addedpropargyl bromide in toluene (80 wt %, 2.33 mL, 1.4 equiv). The reactionmixture was stirred at ambient temperature for 22 h, after which timethe volatiles were concentrated under reduced pressure. The residue waspartitioned between EtOAc (70 mL) and water (40 mL). The organic layerwas separated and treated with charcoal (˜1 g) then dried (Na₂SO₄) andfiltered. The filtrate was concentrated under reduced pressure. Theresidue obtained was crystallized from EtOAc and hexane (3:7). Crop Iafforded 4-bromo-2-(prop-2-ynyloxy)benzaldehyde (893 mg) as colorlessneedles. The mother liquor was concentrated under reduced pressure andcrystallized again from EtOAc and hexane (7:93) to obtain a further CropII of 4-bromo-2-(prop-2-ynyloxy)benzaldehyde (1.902 g). The motherliquor was concentrated again and subjected to one more crystallizationas described before. Crop III yielded additional4-bromo-2-(prop-2-ynyloxy)benzaldehyde (344 mg). All the three cropswere combined to give a total of 3.14 g (87% yield) of4-bromo-2-(prop-2-ynyloxy)benzaldehyde as colorless needles. ¹H NMR (500MHz, CDCl₃) δ 10.43 (s, 1H), 7.74 (d, J=8.2 Hz, 1H), 7.31 (d, J=1.5 Hz,1H), 7.24-7.28 (m, 1H), 4.85 (d, J=2.4 Hz, 2H), 2.64 (t, J=2.4 Hz, 1H);LCMS (Method A) (ESI) m/e 239.0, 241.0 Br pattern [(M+H)⁺, calcd forC₁₀H₇BrO₂ 239.0]; SiO₂ TLC (EtOAc:Hexane=1:9) indicated R_(f) of 0.32compared with an R_(f) of 0.43 for starting material aldehyde.

Part B. (E)-3-(4-bromo-2-(prop-2-ynyloxy)phenyl)acrylaldehyde

A mixture of 4-bromo-2-(prop-2-ynyloxy)benzaldehyde (0.852 g, 3.56 mmol)and formylmethylenetriphenylphosphorane (2.2 g, 7.12 mmol, 2 equiv)suspended in THF (20 mL) under nitrogen was stirred at ambienttemperature for 18 h and then at 50° C. for another 24 h. The reactionmixture was filtered through a bed of silica gel (−25 g) eluting withEtOAc:hexane (1:4, 300 mL). The filtrate was concentrated under reducedpressure and the residue was purified by silica gel chromatography usinga linear gradient of EtOAc:hexane (1:19 to 1:9). Pooled fractionscontaining the title compound and its Z-isomer in the ratio of (39:11,by NMR) was concentrated under reduced pressure to give(E)-3-(4-bromo-2-(prop-2-ynyloxy)phenyl)acrylaldehyde (0.69 g, 2.6 mmol,57% yield). ¹H NMR (500 MHz, CDCl₃) δ 9.71 (d, J=7.6 Hz, 1H), 7.77 (d,J=16.2 Hz, 1H), 7.45 (d, J=8.2 Hz, 1H), 7.26-7.17 (m, 2H), 6.77 (dd,J=16.2, 7.6 Hz, 1H), 4.82 (d, J=2.4 Hz, 1H), 4.80-4.75 (m, 1H), 2.62 (t,J=2.4 Hz, 1H). The Z-isomer showed the aldehydic proton at δ 9.87 (d,J=7.9 Hz) and a smaller cis-coupling (J=11.4 Hz) for the olefinic protonat δ6.22; LCMS (Method B) (ESI) m/e 265.0, 267.0 Br pattern [(M+H)⁺,calcd for C₁₂H₉BrO₂ 265.0].

Part C.(E)-2-(E)-3-(4-bromo-2-(prop-2-ynyloxy)phenyl)allylidene)-1,1-dimethylhydrazine

A solution of (E)-3-(4-bromo-2-(prop-2-ynyloxy)phenyl)acrylaldehyde(2.85 g, 10.8 mmol) in dichloromethane (200 mL) containing anhydrousMgSO₄ (16 g) was cooled in an ice bath with stirring. To the ice-coldsolution was added 1,1-dimethylhydrazine (2.45 mL, 32.4 mmol) dropwiseand the reaction mixture was allowed to warm up to ambient temperatureand was stirred for 18 h. The volatiles were concentrated under reducedpressure and the residue was coevaporated sequentially withdichloromethane (50 mL), dichloroethane (50 mL) and heptane (50 mL).(E)-2-((E)-3-(4-bromo-2-(prop-2-ynyloxy)phenyl)allylidene)-1,1-dimethylhydrazine(2.7 g, 8.79 mmol, 90% yield, 90% purity) was obtained as a yellowpowder. ¹H NMR (500 MHz, CDCl₃) δ 7.39 (d, J=7.9 Hz, 1H), 7.20-7.10 (m,3H), 7.00-6.86 (m, 2H), 4.75 (d, J=2.3 Hz, 2H), 2.95 (s, 6H), 2.58 (t,J=2.3 Hz, 1H); LCMS (Method B) (ESI) m/e 307.0, 309.0 Br pattern[(M+H)⁺, calcd for C₁₄H₁₅BrN₂O 307.0].

Part D. 8-bromo-5H-chromeno[3,4-c]pyridine

A solution of(E)-2-((E)-3-(4-bromo-2-(prop-2-ynyloxy)phenyl)allylidene)-1,1-dimethylhydrazine(116 mg, 374 mmol) and 2,6-di-tert-butyl-4-methylphenol (82 mg, 374mmol) in mesitylene (4.5 mL) was degassed at 50° C. by bubbling argonfor ˜15 min while sonicating in a thick glass vial. The vial was cappedunder argon and heated to 140° C. in an oil bath with stirring for 138 h(5.75 days). The reaction mixture was cooled to ambient temperature andthe solvent was concentrated under reduced pressure. The dark residuewas purified by silica gel chromatography with EtOAc:dichloromethane(1:19) as the eluant. Fractions containing the required product werecombined and concentrated under reduced pressure to give8-bromo-5H-chromeno[3,4-e]pyridine (27 mg, 0.088 mmol, 25% yield basedon 89% purity) as a pale yellow powder. ¹H NMR (500 MHz, CDCl₃) δ 8.63(d, J=5.2 Hz, 1H), 8.45 (s, 1H), 7.62 (d, J=8.2 Hz, 1H), 7.52 (d, J=5.2Hz, 1H), 7.27-7.22 (m, 2H), 5.20 (s, 2H); LCMS (Method A) (ESI) m/e262.0, 264.0 Br pattern [(M+H)⁺, calcd for C₁₄H₁₅BrN₂O 262.0].

Part E. (R)-2-(1-hydroxy-4-methylpentan-2-yl)isoindoline-1,3-dione

The title compound was prepared in 75% yield on a 4 mmol scale asdescribed in WO 2005/041684 A2. The product obtained had similarspectral characteristics as those reported.

Part F. (R)-1-(5H-chromeno[3,4-o]pyridin-8-yloxy)-4-methylpentan-2-amine

Nitrogen was slowly bubbled for 5 min through a suspension of8-bromo-5H-chromeno[3,4-e]pyridine (26 mg, 0.1 mmol),(R)-2-(1-hydroxy-4-methylpentan-2-yl)isoindoline-1,3-dione (116 mg, 0.47mmol, 4.7 equiv),5-(di-tert-butylphosphino)-1′,3′,5′-triphenyl-1′H-1,4′-bipyrazole (30mg, 0.06 mmol, 0.6 equiv), Cs₂CO₃ (49 mg, 0.15 mmol, 1.5 equiv) andPd(OAc)₂ (7 mg, 0.03 mmol, 0.3 equiv) in toluene (0.5 mL) in a thickglass vial. The vial was capped and then heated at 80° C. for 19 h. Thereaction mixture was cooled to ambient temperature and filtered throughcelite, washing with dichloromethane. The combined filtrate wasconcentrated under reduced pressure and the residue obtained waspurified via silica gel chromatography with EtOAc:DCM (1:4) as theeluant. Fractions containing the desired product (with impurities) wereconcentrated under reduced pressure to give(R)-2-(1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione:¹H NMR (500 MHz, CDCl₃) δ 8.54 (d, J=5.2 Hz, 1H), 8.37 (s, 1H),7.89-7.82 (m, 2H), 7.77-7.70 (m, 2H), 7.59 (d, J=8.9 Hz, 1H), 7.41 (d,J=5.5 Hz, 1H), 6.60 (dd, J=8.7, 2.6 Hz, 1H), 6.51 (d, J=2.4 Hz, 1H),5.12 (s, 2H), 4.85-4.75 (m, 1H), 4.57 (t, J=9.5 Hz, 1H), 4.18 (dd,J=9.5, 4.9 Hz, 1H), 2.27-2.17 (m, 1H), 1.63-1.54 (m, 2H), 1.00 (d, J=5.8Hz, 3H), 0.97 (d, J=6.1 Hz, 3H). By proton NMR the mixture wasdetermined to be desired product, reagent and the phosphine oxidederived from the catalyst in an approximately 10:10:3 ratiorespectively. Without further purification this mixture was taken to thenext step of deprotection of phthalimido group as follows: A solution of(R)-2-(1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione(44 mg, 0.102 mmol) in ethanol (2 mL) was combined with hydrazine (0.022mL, 714 mmol) and the solution was stirred at 45° C. for 3 h. Thereaction mixture was cooled to room temperature and diluted withdiethylether (10 mL) then filtered. The filtrate was concentrated underreduced pressure and the residue was purified by preparative HPLC(Method A).(R)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine (23 mg,0.077 mmol, 43% yield for two steps) was obtained as a pale yellow oil.¹H NMR (500 MHz, CD₃OD) δ 8.71-8.57 (m, 2H), 8.24 (d, J=6.4 Hz, 1H),8.08 (m, 1H), 6.95 (dd, J=8.9, 2.4 Hz, 1H), 6.80 (d, J=2.4 Hz, 1H), 5.37(s, 2H), 4.36 (m, 1H), 4.19 (dd, J=10.5, 6.4 Hz, 1H), 3.78-3.66 (m, 1H),1.88-1.76 (m, 1H), 1.75-1.60 (m, 2H), 1.09-0.98 (m, 6H); LCMS (Method A)(ESI) m/e 299.2 [(M+H)⁺, calcd for C₁₈H₂₂N₂O₂ 299.2]; optical rotation:[α]²⁰ _(D) (MeOH)=−5.9°.

Example 2(R)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-3-phenylpropan-2-amine

Part A. (R)-2-(1-hydroxy-3-phenylpropan-2-yl)isoindoline-1,3-dione

The title compound was prepared following the same protocol describedfor the synthesis of(R)-2-(1-hydroxy-4-methylpentan-2-yl)isoindoline-1,3-dione in Example 1,Part E. The compound thus prepared had the properties described inSikoraiova, J. et. al. J. Heterocyclic. Chem. 2002, 39, 383.

Part B. (R)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-3-phenylpropan-2-amine

The title compound was prepared in 46% yield following the same protocoldescribed in Example 1, Part F on a 30 mg (103 mmol) scale. Afterpreparative HPLC (Method B) purification,(R)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-3-phenylpropan-2-amine wasobtained as a pale yellow oil. ¹H NMR (500 MHz, CD₃OD) δ 8.72-8.59 (m,2H), 8.24 (d, J=6.4 Hz, 1H), 8.07 (d, J=8.9 Hz, 1H), 7.43-7.36 (m, 2H),7.36-7.29 (m, 3H), 6.93 (dd, J=8.9, 2.4 Hz, 1H), 6.74 (d, J=2.4 Hz, 1H),5.36 (s, 2H), 4.27 (dd, J=10.7, 3.1 Hz, 1H), 4.11 (dd, J=10.7, 5.5 Hz,1H), 3.96-3.88 (m, 1H), 3.15 (d, J=7.6 Hz, 2H); LCMS (Method A) (ESI)m/e 333.2 [(M+H)⁺, calcd for C₂₁H₂₁N₂O₂ 333.2].

Example 3 (R)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)butan-2-amine

Part A. (R)-2-(1-hydroxybutan-2-yl)isoindoline-1,3-dione

The title compound was prepared following the same protocol describedfor the synthesis of(R)-2-(1-hydroxy-4-methylpentan-2-yl)isoindoline-1,3-dione in Example 1,Part E. The compound thus prepared had the properties described inSikoraiova, J. et. al. J. Heterocyclic. Chem. 2002, 39, 383.

Part B. (R)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)butan-2-amine

The title compound was prepared in 21% yield following the same protocoldescribed in Example 1, Part F on a 26 mg (100 mmol) scale. Afterpreparative HPLC purification (Method B),(R)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)butan-2-amine was obtained as apale yellow oil: ¹H NMR (500 MHz, CD₃OD) δ 8.74-8.60 (m, 2H), 8.24 (d,J=6.4 Hz, 1H), 8.08 (d, J=8.9 Hz, 1H), 6.95 (dd, J=8.9, 2.4 Hz, 1H),6.80 (d, J=2.4 Hz, 1H), 5.37 (s, 2H), 4.36 (dd, J=10.4, 3.4 Hz, 1H),4.21 (dd, J=10.5, 6.6 Hz, 1H), 3.59 (m, 1H), 1.96-1.77 (m, 2H), 1.13 (t,J=7.6 Hz, 3H); LCMS (Method A) (ESI) m/e 271.1 [(M+H)⁺, calcd forC₁₆H₁₉N₂O₂ 271.1].

Example 4 (S)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)butan-2-amine

Part A. (S)-2-(1-hydroxybutan-2-yl)isoindoline-1,3-dione

The title compound was prepared following the same protocol describedfor the synthesis of(R)-2-(1-hydroxy-4-methylpentan-2-yl)isoindoline-1,3-dione in Example 1,Part E. The compound thus prepared had the properties described(Sikoraiova, J. et. al. J. Heterocyclic. Chem. 2002, 39, 383).

Part B. (S)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)butan-2-amine

The title compound was prepared in 19% yield following the same protocoldescribed in Example 1, Part F on a 26 mg (100 mmol) scale. Afterpreparative HPLC purification (Method C),(S)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)butan-2-amine was obtained as apale yellow oil: ¹H NMR (500 MHz, CD₃OD) δ 8.74-8.60 (m, 2H), 8.24 (d,J=6.4 Hz, 1H), 8.08 (d, J=8.9 Hz, 1H), 6.95 (dd, J=8.9, 2.4 Hz, 1H),6.80 (d, J=2.4 Hz, 1H), 5.37 (s, 2H), 4.36 (dd, J=10.4, 3.4 Hz, 1H),4.21 (dd, J=10.5, 6.6 Hz, 1H), 3.59 (m, 1H), 1.96-1.77 (m, 2H), 1.13 (t,J=7.6 Hz, 3H); LCMS (Method A) (ESI) m/e 271.1 [(M+H)⁺, calcd forC₁₆H₁₉N₂O₂ 271.1].

Example 5(S)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine

Part A. 4-bromonicotinaldehyde

To a stirred solution of diisopropylamine (9.02 mL, 63.3 mmol) in THF(75 mL) at −78° C. was added n-butyllithium (1.6 M in hexane) (30 mL, 76mmol) dropwise under nitrogen atmosphere. After complete addition thesolution was stirred for 30 min at −78° C. 4-Bromopyridine HCl (5 g,31.6 mmol) was added portionwise and the resultant solution stirred at−78° C. for 1 h. DMF (2.94 mL, 38.0 mmol) was then added dropwise at−78° C. to the solution. The reaction mixture was warmed to roomtemperature slowly and stirred for 12 h. The reaction mixture wasquenched with 3 N HCl and stirred for 2 h. The solution was neutralizedwith saturated sodium bicarbonate solution, extracted with EtOAc (75mL), dried over sodium sulfate and concentrated under reduced pressureto give 4-bromonicotinaldehyde (3.75 g, 20.16 mmol, 64% yield). Thecrude product was used without purification in the next step. ¹H NMR(400 MHz, CDCl₃) δ 10.39 (s, 1H), 9.00 (s, 1H), 8.56 (d, J=5.2 Hz, 1H),7.62 (d, J=5.2 Hz, 1H).

Part B. 4-(4-chloro-2-fluorophenyl)nicotinaldehyde

To a mixture of 4-bromonicotinaldehyde (3.00 g, 16.13 mmol),(4-chloro-2-fluorophenyl)boronic acid (2.81 g, 16.13 mmol), cesiumcarbonate (10.51 g, 32.3 mmol) and Pd(PPh₃)₄ (0.932 g, 0.806 mmol) wasadded THF (50 mL) and water (8 mL). Nitrogen gas was bubbled through thestirred suspension for 5 min. The reaction mixture was stirred undernitrogen atmosphere at 85° C. for 6 h. The reaction mixture was thencooled to room temperature and filtered through celite. The filtrate wasdiluted with ethyl acetate (30 mL) and washed with water (1×25 mL) andbrine (1×25 mL). The combined organic extracts were dried over sodiumsulfate and concentrated under reduced pressure. The crude residue waspurified via silica gel chromatography (ethyl acetate/hexanes) to yield4-(4-chloro-2-fluorophenyl)nicotinaldehyde (1.5 g, 6.37 mmol, 39% yieldfor two steps). ¹H NMR (400 MHz, CDCl₃) δ 10.01 (s, 1H), 9.18 (s, 1H),8.86 (d, J=5.1 Hz, 1H), 7.30 (m, 4H).

Part C. (4-(4-chloro-2-fluorophenyl)pyridin-3-yl)methanol

To a solution of 4-(4-chloro-2-fluorophenyl)nicotinaldehyde (3 g, 12.73mmol) in a mixture of methanol (5 mL) and tetrahydrofuran (5 mL) cooledto 0° C. was added NaBH₄ (0.722 g, 19.10 mmol) and the solution stirredfor 30 min. The reaction was quenched by addition of water (10 mL). Thesolution was extracted with ethyl acetate (3×15 mL). The combinedorganic extracts were washed with water (1×15 mL) and brine (1×15 mL),dried with sodium sulfate and concentrated under reduced pressure toyield (4-(4-chloro-2-fluorophenyl)pyridin-3-yl)methanol that was usedwithout further purification in the next step. LCMS (ESI) m/e 238[(M+H)⁺, calcd for C₁₂H₁₀ClFNO 238.0].

Part D. 8-Chloro-5H-chromeno[3,4-c]pyridine

To a cooled solution of(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)methanol (2.89 g, 12.14 mmol)in THF (10 mL) at 0° C. was added a sodium hydride (1.94 g, 48.6 mmol)suspension in THF (10 mL) and the resultant mixture was stirred at 0° C.for 40 min. The reaction was quenched by addition of cold water (15 mL)and extracted with ethyl acetate (3×15 mL). The combined organicextracts were dried with sodium sulfate and concentrated under reducedpressure. The residue so obtained was purified by column chromatography(50% ethyl acetate in pet ether) to afford8-chloro-5H-chromeno[3,4-c]pyridine (1.6 g, 7.35 mmol, 61% yield) as awhite solid. ¹H NMR (400 MHz, MeOD) δ 8.54 (d, J=5.60 Hz, 1H), 8.43 (s,1H), 7.89 (d, J=8.40 Hz, 1H), 7.76 (d, J=5.60 Hz, 1H), 7.14 (dd, J=2.40,8.40 Hz, 1H), 7.07 (d, J=2.00 Hz, 1H), 5.24 (s, 2H); LCMS (ESI) m/e 218[(M±H)⁺, calcd for C₁₂H₉ClNO 218.0].

Part E.(S)-2-(1-((5H-chromeno[3,4-d]pyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione

To a stirred suspension of 8-chloro-5H-chromeno[3,4-c]pyridine (1 g,4.59 mmol), (S)-2-(1-hydroxy-4-methylpentan-2-yl)isoindoline-1,3-dione(3.43 g, 13.88 mmol),di-tert-butyl(2′,4′,6′-triisopropyl-[1,1′-biphenyl]-2-yl)phosphine (1.17g, 2.76 mmol) and cesium carbonate (2.245 g, 6.89 mmol) in toluene (4mL) was added palladium (II) acetate (0.309 g, 1.38 mmol). Nitrogen gaswas bubbled through the mixture for 5 min, and then the mixture washeated at 80° C. for 14 h. The reaction was diluted with ethyl acetate(25 mL) and filtered through celite. The filtrate was washed with water(1×20 mL) and brine (1×20 mL), dried over sodium sulfate andconcentrated under reduced pressure. The residue was purified via silicagel column chromatography (60% ethyl acetate in hexanes) to afford(S)-2-(1-((5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione(2 g, 4.67 mmol, quantitative yield) as a semi solid. LCMS (ESI) m/e 429[(M+H)⁺, calcd for C₂₆H₂₅N₂O₄ 429.2].

Part F. (S)-1-(5H-chromeno[3,4-d]pyridin-8-yloxy)-4-methylpentan-2-amine

To the solution of(S)-2-(1-((5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)isoindoline-1,3-dione(1.47 g, 3.43 mmol) in ethanol (8 mL) under a nitrogen atmosphere wasadded hydrazine (0.754 mL, 24.02 mmol) at rt and the reaction mixturewas then stirred at 45° C. in an oil bath for 3 h. A white precipitateformed during the course of the reaction. The reaction mixture wasquenched by addition of water (15 mL) and the product was extracted withethyl acetate (3×25 mL). The combined organic extracts were dried withsodium sulfate and concentrated under reduced pressure. The residue waspurified by preparative HPLC on a reverse phase C-18 column using 10 mMammonium acetate buffer and acetonitrile gradient. The fractions wereconcentrated under reduced pressure and lyophilized to yield(S)-1-((5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine (0.4g, 0.970 mmol, 39% yield) as a yellow solid. ¹H NMR (400 MHz, CD₃OD) δ8.48 (d, J=5.6 Hz, 1H), 8.37 (s, 1H), 7.86 (d, J=8.8 Hz, 1H), 7.70 (d,J=5.2 Hz, 1H), 6.83 (dd, J=8.4, 2.4, 1H), 6.70 (d, J=2.4 Hz, 1H), 5.20(s, 2H), 4.28 (dd, J=11.2, 3.6, 1H), 4.10 (dd, J=10.4, 6.4, 1H), 3.66(m, 1H), 1.82 (m, 1H), 1.69-1.63 (m, 2H), 1.04 (m, 6H); LCMS (ESI) m/e299.2 [(M+H)⁺, calcd for C₁₈H₂₂N₂O₂ 299.38]; LC/MS retention time(Method E): t_(R)=1.78 min. HPLC retention time (method A): t_(R)=7.97min; CHIRAL HPLC retention time (method C): t_(R)=12.87 min; opticalrotation: [α]20_(D) (MeOH)=+7.1°.

Example 6(2S)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-amine

Part A. 1-(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)ethanol

To a solution of 4-(4-chloro-2-fluorophenyl)nicotinaldehyde (0.12 g,0.509 mmol) (prepared as in Example 5, Part B) in anhydrous THF (15 mL)was added methyl magnesium bromide (3.0 M in diethyl ether) (0.364 g,3.06 mmol) at −60° C. dropwise. After complete addition the solution wasstirred at −60° C. for 10 min. The reaction mixture was then allowed towarm to room temperature and stirred for 1 h. The reaction was quenchedby addition of saturated aqueous ammonium chloride solution (15 mL). Theorganics were extracted with ethyl acetate (3×20 mL) and washed withwater (1×15 mL) and brine (1×15 mL). The combined organic extracts weredried over sodium sulfate and concentrated under reduced pressure. Theresidue was purified via preparative TLC (20% ethyl acetate in hexane)to afford 1-(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)ethanol (40 mg,0.159 mmol, 31% yield) as an off-white solid: ¹H NMR (400 MHz, CDCl₃) δ8.89 (s, 1H), 8.50 (s, 1H), 7.15-7.26 (m, 3H), 7.07 (d, J=3.8 Hz, 1H),4.82 (q, J=6.3 Hz, 1H), 3.06 (bs, 1H), 1.40 (d, J=6.3 Hz, 3H).

Part B. 8-Chloro-5-methyl-5H-chromeno[3,4-c]pyridine

To a stirred suspension of NaH (3.81 mg, 0.159 mmol) in anhydrous THF (5mL), was added a THF (5 mL) solution of1-(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)ethanol (20 mg, 0.079 mmol)dropwise and the reaction mixture was stirred at room temperature for 4h. The reaction was quenched by addition of saturated aqueous ammoniumchloride solution (15 mL) and the product was extracted with ethylacetate (3×20 mL). The combined organics were washed with water (1×15mL) and brine (1×15 mL), dried over sodium sulfate and concentratedunder reduced pressure. The residue was purified via preparative TLC(40% ethyl acetate in hexane) to afford8-chloro-5-methyl-5H-chromeno[3,4-c]pyridine (12 mg, 0.052 mmol, 63%yield). ¹H NMR (400 MHz, CDCl₃) δ 8.59 (d, J=5.2 Hz, 1H), 8.42 (s, 1H),7.66 (d, J=8.3 Hz, 1H), 7.49 (d, J=5.2 Hz, 1H), 7.06 (m, 2H), 5.36 (q,J=6.6 Hz, 1H), 1.66 (d, J=6.6 Hz, 3H); LCMS (ESI) m/e 232 [(M+H)⁺, calcdfor C₁₃H₁₁ClNO 232.1].

Part C.2-((2S)-4-methyl-1-(5-methyl-5H-chromeno[3,4-e]pyridin-8-yloxy)pentan-2-yl)isoindoline-1,3-dione

To a stirred solution of 8-bromo-5-methyl-5H-chromeno[3,4-c]pyridine(200 mg, 0.724 mmol) in toluene (4 mL), were added(S)-2-(1-hydroxy-4-methylpentan-2-yl)isoindoline-1,3-dione (537 mg,2.173 mmol),di-tert-butyl(2′,4′,6′-triisopropyl-[1,1′-biphenyl]-2-yl)phosphine (185mg, 0.435 mmol), cesium carbonate (354 mg, 1.086 mmol) and palladium(II) acetate (48.8 mg, 0.217 mmol). Nitrogen was bubbled through thereaction mixture for 10 min and the mixture was heated at 80° C. 12 h.The reaction mixture was cooled to room temperature and filtered throughcelite and residue rinsed with ethyl acetate. The filtrate wasconcentrated under reduced pressure and purified via prep TLC (60% ethylacetate in pet ether) to afford2-((2S)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-yl)isoindoline-1,3-dione(205 mg, 0.463 mmol, 64% yield). LCMS (ESI) m/e 443.2 [(M+H)⁺, calcd forC₂₇H₂₇N₂O₄ 443.2]; LC/MS retention time (Method C): t_(R)=2.27 min.

Part D.(2S)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-amine

To a solution of1-((2S)-4-methyl-1-((5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)pyrrolidine-2,5-dione(205 mg, 0.520 mmol) in ethanol (20 mL) was added hydrazine monohydrate(260 mg, 5.20 mmol). The reaction mixture was heated at 45° C. for 5 h.The reaction mixture was cooled to room temperature, ether (50 mL) wasadded, and the mixture filtered. The filtrate was concentrated underreduced pressure. The residue was dissolved in dichloromethane (2 mL)and cooled to 0° C. 4 M HCl in dioxane (2 mL) was added the solution wasstirred for 1 h. The reaction mixture was concentrated under reducedpressure and residue was dissolved in water (5 mL). The aqueous layerwas washed with ethyl acetate (3×25 mL). To the aqueous layer was addedacetonitrile (2 mL) and the solution was lyophilized to yield(2S)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-amineas an HCl salt. The crude product was purified via preparative HPLC(0.1% TFA in water and MeCN) to afford(2S)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-amine,2TFA (145 mg, 0.268 mmol, 52% yield): ¹H NMR (400 MHz, CD₃OD) δ 8.64 (d,J=6.1 Hz, 1H), 8.60 (s, 1H), 8.19 (d, J=6.1 Hz, 1H), 8.05 (d, J=8.9 Hz,1H), 6.92 (m, 1H), 6.78 (d, J=2.5 Hz, 1H), 5.5 (m, 1H), 4.35 (m, 1H),4.17 (m, 1H), 3.72 (m, 1H), 1.79 (m, 1H), 1.73 (d, J=6.6 Hz, 3H), 1.67(m, 2H), 1.04 (m, 6H); LCMS (ESI) m/e 313.2 [(M+H)⁺, calcd forC₁₉H₂₅N₂O₂ 313.2]; LC/MS retention time (Method E): t_(R)=1.69 min.

The diastereomeric mixture so obtained was resolved by preparativechiral HPLC (0.2% DEA in n-hexane, ethanol).

Diastereomer 1

Obtained diastereomer 1 (0.023 g, 0.072 mmol, 27% yield) as a paleyellow oil: ¹H NMR (400 MHz, CD₃OD) δ 8.46 (d, J=5.36 Hz, 1H), 8.36 (s,1H), 7.83 (d, J=8.7 Hz, 1H), 7.69 (d, J=5.2 Hz, 1H), 6.76 (m, 1H), 6.62(d, J=2.48 Hz, 1H), 5.39 (m, 1H), 4.03 (m, 1H), 3.85 (m, 1H), 3.32 (m,1H), 1.82 (m, 1H), 1.64 (m, 3H), 1.43 (m, 2H), 0.99 (m, 6H); HPLCretention time (method A): t_(R)=7.41 min; HPLC retention time (methodB): t_(R)=8.97 min. CHIRAL HPLC retention time (method B): t_(R)=14.88min.

Diastereomer 2

Obtained diastereomer 2 (0.022 g, 0.070 mmol, 26% yield) as a paleyellow oil: ¹H NMR (400 MHz, CD₃OD) δ 8.46 (d, J=5.36 Hz, 1H), 8.36 (s,1H), 7.83 (d, J=8.7 Hz, 1H), 7.69 (d, J=5.2 Hz, 1H), 6.76 (m, 1H), 6.62(d, J=2.48 Hz, 1H), 5.39 (m, 1H), 4.03 (m, 1H), 3.85 (m, 1H), 3.33 (m,1H), 1.82 (m, 1H), 1.64 (m, 3H), 1.43 (m, 2H), 0.99 (m, 6H); HPLCretention time (method A): t_(R)=7.45 min; HPLC retention time (methodB): t_(R)=8.93 min. CHIRAL HPLC retention time (method B): t_(R)=19.41min.

Example 7(2R)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-amine

(2R)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-aminewas prepared in analogous fashion to Example 6. The diastereomericmixture so obtained was resolved by preparative chiral HPLC (0.2% DEA inn-hexane, ethanol).

Diastereomer 1

Obtained diastereomer 1 (19 mg, 0.061 mmol, 26% yield) as a yellowsolid: ¹H NMR (400 MHz, CD₃OD) δ 8.67 (d, J=6.40 Hz, 1H), 8.65 (s, 1H),8.26 (d, J=6.40 Hz, 1H), 8.09 (d, J=8.80 Hz, 1H), 6.95 (q, J=2.40 Hz,1H), 6.80 (d, J=2.40 Hz, 1H), 5.58 (q, J=6.40 Hz, 1H), 4.36 (q, J=3.20Hz, 1H), 4.18 (q, J=6.40 Hz, 1H), 3.73 (q, J=2.80 Hz, 1H), 1.74-1.85 (m,1H), 1.72 (d, J=2.80 Hz, 3H), 1.61-1.70 (m, 2H), 1.05 (q, J=3.60 Hz,6H); LCMS (ESI) m/e 313.2 [(M+H)⁺, calcd for C₁₉H₂₅N₂O₂ 313.2]; LC/MSretention time (Method E): t_(R)=1.73 min; HPLC retention time (methodA): t_(R)=8.06 min; HPLC retention time (method B): t_(R)=9.11 min;Chiral HPLC retention time (method B): t_(R)=15.34 min.

Diastereomer 2

Obtained diastereomer 2 (31 mg, 0.099 mmol, 43% yield) as a yellowsolid:

¹H NMR (400 MHz, CD₃OD) δ 8.68 (d, J=6.40 Hz, 1H), 8.65 (s, 1H), 8.27(d, J=6.40 Hz, 1H), 8.09 (d, J=8.80 Hz, 1H), 6.95 (dd, J=2.40, 8.80 Hz,1H), 6.80 (d, J=2.80 Hz, 1H), 5.58 (q, J=6.80 Hz, 1H), 4.36 (dd, J=3.60,10.60 Hz, 1H), 4.19 (q, J=6.40 Hz, 1H), 3.70-3.76 (m, 1H), 1.74-1.85 (m,1H), 1.72 (d, J=3.20 Hz, 3H), 1.61-1.70 (m, 2H), 1.05 (q, J=4.00 Hz,6H); LCMS (ESI) m/e 313.2 [(M+H)⁺, calcd for C₁₉H₂₅N₂O₂ 313.2]; LC/MSretention time (Method E): t_(R)=1.72 min; HPLC retention time (methodB): t_(R)=13.14 min, Chiral HPLC retention time (method B): t_(R)=12.06min.

Example 8(2S)-1-(5-cyclopropyl-5H-chromeno[3,4-c]-pyridin-8-yloxy)-4-methylpentan-2-amine

Part A. (4-(4-chloro-2-fluorophenyl)pyridin-3-yl)(cyclopropyl)methanol

To a solution of 4-(4-chloro-2-fluorophenyl)nicotinaldehyde (1.6 g, 6.79mmol) (prepared as in Example 5, Part B) in THF (32 mL) cooled to −78°C., was added cyclopropylmagnesium bromide (27.2 mL, 13.58 mmol)dropwise over a period of 20 min. The reaction mixture was allowed tostir at −78° C. for 3 h. The dry ice bath was removed and reactionmixture was brought to room temperature. The reaction mixture wasquenched by addition of saturated aqueous ammonium chloride solution (30mL). The reaction mixture was extracted with ethyl acetate (3×50 mL).The combined organic extracts were washed with brine (1×50 mL), driedover sodium sulfate and concentrated under reduced pressure. The crudeproduct was purified by silica gel chromatography (30% ethyl acetate inpet ether) to afford(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)(cyclopropyl)methanol (900 mg,3.24 mmol, 48% yield). LCMS (ESI) m/e 278.0 [(M+H)⁺, calcd forC₁₅H₁₄ClFNO 278.1]; LC/MS retention time (Method C): t_(R)=1.62 min.

Part B. 8-Chloro-5-cyclopropyl-5H-chromeno[3,4-c]pyridine

To a suspension of NaH (389 mg, 9.72 mmol) in THF (9 mL) cooled to 0°C., was added(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)(cyclopropyl)methanol (900 mg,3.24 mmol) in THF (9 mL) dropwise over a period of 10 min. The reactionmixture was stirred at 0° C. for 15 min and then warmed to roomtemperature and stirred for 15 h. The reaction mixture was quenched byaddition of cold water (10 mL) and extracted with ethyl acetate (3×25mL). The combined organic extracts were washed with brine (1×25 mL),dried over sodium sulfate and concentrated under reduced pressure. Thecrude residue was purified via silica gel column chromatography (ethylacetate/hexanes) to give8-chloro-5-cyclopropyl-5H-chromeno[3,4-c]pyridine (630 mg, 2.45 mmol,75% yield). LCMS (ESI) m/e 258.0 [(M+H)⁺, calcd for C₁₅H₁₃ClNO 258.1];LC/MS retention time (Method C): t_(R)=2.08 min.

Part C.tert-Butyl-(2S)-1-(5-cyclopropyl-5H-chromeno[3,4-e]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

To a stirred solution of8-chloro-5-cyclopropyl-5H-chromeno[3,4-c]pyridine (275 mg, 1.067 mmol)in toluene (3 mL) was added(S)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate (696 mg, 3.20mmol), cesium carbonate (427 mg, 1.310 mmol),di-tert-butyl(2′,4′,6′-triisopropyl-[1,1′-biphenyl]-2-yl)phosphine (272mg, 0.640 mmol) and palladium (II) acetate (71.9 mg, 0.320 mmol).Nitrogen was bubbled through the reaction mixture for 10 min then themixture was heated at 80° C. for 12 h. The reaction mixture was cooledto room temperature and filtered through celite. The filtrate wasdiluted with water (10 mL) and extracted with ethyl acetate (3×15 mL).The combined organic extracts were washed with brine (1×15 mL), driedover sodium sulfate and concentrated under reduced pressure. The crudeproduct was purified via silica gel chromatography (ethyl acetate/petether) to givetert-butyl-(2S)-1-(5-cyclopropyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate(250 mg, 0.57 mmol, 50% yield). LCMS (ESI) m/e 439.2 [(M+H)⁺, calcd forC₂₆H₃₅N₂O₄ 439.3]; LC/MS retention time (Method C): t_(R)=2.16 min.

Part D.(2S)-1-(5-cyclopropyl-5H-chromeno[3,4-e]pyridin-8-yloxy)-4-methylpentan-2-amine

To a solution oftert-butyl((2S)-1-((5-cyclopropyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(250 mg, 0.570 mmol) in CH₂Cl₂ (4 mL) cooled to 0° C. was added 1N HClin dioxane (2 mL, 0.570 mmol) slowly over a period of 5 min. Thereaction mixture was stirred at 0° C. for 5 min then was warmed to roomtemperature and allowed to stir for 2 h. The solvents were removed byconcentration under reduced pressure. The crude product was washed withethyl acetate to yield(2S)-1-(5-cyclopropyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amineas an HCl salt (240 mg, 42% yield). LCMS (ESI) m/e 339.2 [(M+H)⁺, calcdfor C₂₁H₂₇N₂O₂ 339.2]; LC/MS retention time (Method C): t_(R)=1.28 min.The diastereomeric mixture of amines was resolved by chiral preparativeHPLC (0.2% DEA in n-hexane, ethanol).

Diastereomer 1

Obtained diastereomer 1 (45 mg, 0.133 mmol, 23% yield) as a yellow oil.¹H NMR (400 MHz, CD₃OD) δ 8.48 (s, 1H), 8.47 (d, J=5.5 Hz, 1H), 7.83 (d,J=8.7 Hz, 1H), 7.70 (d, J=5.3 Hz, 1H), 6.75 (m, 1H), 6.65 (d, J=2.4 Hz,1H), 4.52 (d, J=8.9 Hz, 1H), 4.04 (m, 1H), 3.87 (m, 1H), 3.29 (m, 1H),1.82 (m, 1H), 1.39 (m, 3H), 0.99 (m, 6H), 0.70 (m, 2H), 0.61 (m, 1H),0.52 (m, 1H); LCMS (ESI) m/e 339.2 [(M+F)⁺, calcd for C₂₁H₂₇N₂O₂ 339.2];LC/MS retention time (Method C): t_(R)=1.46 min; HPLC retention time(method A): t_(R)=8.92 min; HPLC retention time (method B): t_(R)=10.33min; Chiral HPLC retention time (method C): t_(R)=10.3 min.

Diastereomer 2

Obtained diastereomer 2 (35 mg, 0.103 mmol, 18% yield) as a yellow oil.¹H NMR (400 MHz, CD₃OD) δ 8.48 (s, 1H), 8.47 (d, J=5.4 Hz, 1H), 7.83 (d,J=8.7 Hz, 1H), 7.70 (d, J=5.3 Hz, 1H), 6.75 (m, 1H), 6.65 (d, J=2.4 Hz,1H), 4.52 (d, J=8.9 Hz, 1H), 4.04 (m, 1H), 3.85 (m, 1H), 3.33 (m, 1H),1.83 (m, 1H), 1.39 (m, 3H), 0.99 (m, 6H), 0.70 (m, 2H), 0.53-0.61 (m,2H); LCMS (ESI) m/e 339.2 [(M+H)⁺, calcd for C₂₁H₂₇N₂O₂ 339.2]; LC/MSretention time (Method C): t_(R)=1.46 min; HPLC retention time (methodA): t_(R)=8.89 min; HPLC retention time (method B): t_(R)=10.34 min;Chiral HPLC retention time (method C): t_(R)=14.11 min.

Example 9(2R)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-amine

(2R)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-aminewas prepared in analogous fashion to Example 8. The diastereomericmixture was resolved using chiral prep HPLC (0.2% DEA in n-hexane andethanol).

Diastereomer 1

Obtained diastereomer 1 (0.03 g, 0.089 mmol, 19% yield) as a yellow oil:¹H NMR (400 MHz, CD₃OD) δ 8.48 (d, J=1.60 Hz, 1H), 8.47 (s, 1H), 7.83(d, J=8.80 Hz, 1H), 7.70 (d, J=5.20 Hz, 1H), 6.76 (dd, J=2.80, 8.60 Hz,1H), 6.66 (d, J=2.40 Hz, 1H), 4.52 (d, J=9.20 Hz, 1H), 4.05 (dd, J=3.60,9.40 Hz, 1H), 3.87 (q, J=7.20 Hz, 1H), 3.32-3.33 (m, 1H), 1.81-1.84 (m,1H), 1.32-1.52 (m, 3H), 0.98-1.02 (m, 6H), 0.71 (dd, J=2.80, 4.60 Hz,2H), 0.50-0.54 (m, 2H); LCMS (ESI) m/e 339.2 [(M+H)⁺, calcd forC₂₁H₂₇N₂O₂ 339.2]; LC/MS retention time (Method C): t_(R)=1.33 min; HPLCretention time (method A): t_(R)=4.51 min; HPLC retention time (methodB): t_(R)=5.18 min; Chiral HPLC retention time (method C): t_(R)=11.01min.

Diastereomer 2

Obtained diastereomer 2 (0.028 g, 0.083 mmol, 18% yield) as a yellowoil: ¹H NMR (400 MHz, CD₃OD) δ 8.48 (d, J=1.60 Hz, 1H), 8.47 (s, 1H),7.83 (d, J=8.80 Hz, 1H), 7.70 (d, J=5.60 Hz, 1H), 6.75 (dd, J=2.40, 8.80Hz, 1H), 6.65 (d, J=2.40 Hz, 1H), 4.52 (d, J=9.20 Hz, 1H), 4.03 (dd,J=3.60, 9.40 Hz, 1H), 3.86 (dd, J=7.20, 9.40 Hz, 1H), 3.20-3.28 (m, 1H),1.79-1.86 (m, 1H), 1.38-1.46 (m, 3H), 1.00 (q, J=6.40 Hz, 6H), 0.72 (d,J=2.80 Hz, 2H), 0.51-0.65 (m, 2H), LCMS (ESI) m/e 339.2 [(M+H)⁺, calcdfor C₂₁H₂₇N₂O₂ 339.2]; LC/MS retention time (Method C): t_(R)=1.34 min;HPLC retention time (method A): t_(R)=4.55 min; HPLC retention time(method B): t_(R)=5.18 min; Chiral HPLC retention time (method C):t_(R)=14.57 min.

Example 10(2S)-1-(5-ethyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine

Part A. 1-(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)prop-2-en-1-ol

To a stirred solution of 4-(4-chloro-2-fluorophenyl)nicotinaldehyde (0.5g, 2.122 mmol) (prepared as in Example 5, Part B) in THF (25 mL) at −70°C. was added vinylmagnesium bromide (1.0 M in THF) (6.37 mL, 6.64 mmol)dropwise and the solution was stirred at this temperature for 45 min.The reaction was quenched with saturated aqueous ammonium chloridesolution (20 mL) and extracted with ethyl acetate (2×15 mL). Thecombined organic extracts were washed with brine (1×15 mL), dried oversodium sulfate and concentrated under reduced pressure. The crudeproduct was used without purification in the next step. LCMS (ESI) m/e264 [(M+H)⁺, calcd for C₁₄H₁₂ClFNO 264.0]; LC/MS retention time (MethodC): t_(R)=1.59 min.

Part B. 8-chloro-5-vinyl-5H-chromeno[3,4-c]pyridine

To a stirred suspension of NaH (0.182 g, 7.58 mmol) in THF (30 mL) wasadded 1-(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)prop-2-en-1-ol (0.5 g,1.896 mmol) dissolved in THF (5 mL) and the reaction mixture was stirredat room temperature for 2 h. The reaction was quenched by addition ofsaturated aqueous ammonium chloride solution (5 mL) and extracted withethyl acetate (3×10 mL). The combined organic extracts were washed withbrine (1×10 mL), dried over sodium sulfate and concentrated underreduced pressure. The crude 8-chloro-5-vinyl-5H-chromeno[3,4-c]pyridinewas used without purification in the next step. ¹H NMR (400 MHz, CDCl₃)δ 8.61 (d, J=5.2 Hz, 1H), 8.40 (s, 1H), 7.65 (d, J=8.8 Hz, 1H), 7.5 (d,J=5.2 Hz, 1H), 7.06 (d, J=2.2 Hz, 2H), 6.09 (m, 1H), 5.70 (d, J=6.2 Hz,1H), 5.37 (m, 1H), 5.28 (m, 1H).

Part C.2-((2S)-4-methyl-1-(5-vinyl-5H-chromeno[3,4-e]pyridin-8-yloxy)pentan-2-yl)isoindoline-1,3-dione

To a stirred suspension of 8-chloro-5-vinyl-5H-chromeno[3,4-c]pyridine(0.2 g, 0.821 mmol),(S)-2-(1-hydroxy-4-methylpentan-2-yl)isoindoline-1,3-dione (0.609 g,2.462 mmol), 2-di-tert-butylphosphino-2,4,6-triisopropylbiphenyl (0.209g, 0.492 mmol), and cesium carbonate (0.401 g, 1.231 mmol) in toluene(25 mL) was added palladium (II) acetate (0.055 g, 0.246 mmol). Nitrogengas was bubbled through the mixture for 5 min, and then the reactionmixture was heated to 80° C. for 14 h. The reaction was diluted withethyl acetate (25 mL) and filtered through celite. The filtrate waswashed with water (1×20 mL) and brine (1×20 mL), dried over sodiumsulfate and concentrated under reduced pressure. The residue waspurified via silica gel column chromatography (60% ethyl acetate inhexanes) to afford2-((2S)-4-methyl-1-(5-vinyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-yl)isoindoline-1,3-dione(0.3 g, 0.660 mmol, 40% yield for three steps). LCMS (ESI) m/e 455.2[(M+H)⁺, calcd for C₂₈H₂₇N₂O₄ 455.2]; LC/MS retention time (Method C):t_(R)=2.16 min.

Part D.2-((2S)-1-(5-ethyl-5H-chromeno[3,4-e]pyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione

To a stirred solution of2-((2S)-4-methyl-1-((5-vinyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)isoindoline-1,3-dione(0.3 g, 0.660 mmol) in methanol (15 mL) was added 10% palladium oncarbon (0.070 g, 0.660 mmol). The resultant mixture was stirred at roomtemperature under a hydrogen atmosphere (1 atm) for 12 h. The reactionmixture was then filtered through celite and concentrated under reducedpressure to yield crude2-((5)-1-(5-ethyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione(0.28 g, 0.221 mmol, 33% crude yield); LCMS (ESI) m/e 457.2 [(M+H)⁺,calcd for C₂₈H₂₉N₂O₄ 457.2]; LC/MS retention time (Method C): t_(R)=2.32min.

Part E.(2S)-1-(5-ethyl-5H-chromeno[3,4-e]pyridin-8-yloxy)-4-methylpentan-2-amine

To a stirred solution of2-((2S)-1-(5-ethyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-yl)isoindoline-1,3-dione(0.25 g, 0.548 mmol) in ethanol (15 mL) was added hydrazine (0.172 mL,5.48 mmol) and the reaction mixture was stirred at 40° C. for 6 h. Thereaction was cooled to room temperature then diluted with DCM (20 mL)and filtered through a bed of celite. The filtrate was concentratedunder reduced pressure and purified by preparative HPLC (0.1% TFA inwater and methanol) to yield(2S)-1-((5-ethyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine(40 mg, 21% yield). The diastereomeric mixture was resolved by SFC (0.5%DEA in methanol).

Diastereomer 1

Diastereomer 1(2S)-1-((5-ethyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine(12 mg, 0.037 mmol, 7% yield) was obtained as an off-white sticky solid.¹H NMR (400 MHz, CD₃OD) δ 8.45 (d, J=5.4 Hz, 1H), 8.32 (s, 1H), 7.81 (d,J=8.7 Hz, 1H), 7.69 (d, J=5.3 Hz, 1H), 6.74 (m, 1H), 6.62 (d, J=2.4 Hz,1H), 5.21 (m, 1H), 4.02 (m, 1H), 3.83 (m, 1H), 3.25 (m, 1H), 1.94 (m,1H), 1.79 (m, 2H), 1.42 (m, 2H), 1.06 (m, 3H), 0.99 (m, 6H); LCMS (ESI)m/e 327.2 [(M+H)⁺, calcd for C₂₀H₂₇N₂O₂ 327.2]; LC/MS retention time(Method C): t_(R)=1.48 min; HPLC retention time (method B): t_(R)=14.09min.

Diastereomer 2: Diastereomer 2(2S)-1-((5-ethyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine(13 mg, 0.04 mmol, 7% yield) was obtained as an off-white sticky solid:¹H NMR (400 MHz, CD₃OD) δ 8.45 (d, J=5.4 Hz, 1H), 8.32 (s, 1H), 7.81 (d,J=8.7 Hz, 1H), 7.69 (d, J=5.3 Hz, 1H), 6.74 (m, 1H), 6.62 (d, J=2.4 Hz,1H), 5.21 (m, 1H), 4.02 (m, 1H), 3.83 (m, 1H), 3.25 (m, 1H), 1.94 (m,1H), 1.79 (m, 2H), 1.42 (m, 2H), 1.06 (m, 3H), 0.99 (m, 6H); LCMS (ESI)m/e 327.2 [(M+H)⁺, calcd for C₂₀H₂₇N₂O₂ 327.2]; LC/MS retention time(Method C): t_(R)=1.48 min; HPLC retention time (method B): t_(R)=13.85min.

Example 11(S)-8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-5-one

Part A. methyl 4-chloronicotinate

To a solution of 4-chloronicotinic acid (0.5 g, 3.17 mmol) in CH₂Cl₂ (60mL) was added oxalyl chloride (1.007 g, 7.93 mmol) dropwise at roomtemperature followed by the addition of DMF (0.4 mL). The solution wasstirred at room temperature for 3 h. Methanol (1.9 mL, 46.8 mmol) wasadded dropwise and the clear solution was further stirred for 30 min.The solvent was evaporated under reduced pressure to yield methyl4-chloronicotinate (0.67 g, 3.90 mmol, 50% yield). LCMS (ESI) m/e 172.5[(M+H)⁺, calcd for C₇H₇ClNO₂ 172.0]; LCMS retention time (Method D):t_(R)=1.15 min.

Part B. methyl 4-(4-chloro-2-fluorophenyl)nicotinate

To a stirred solution of methyl 4-chloronicotinate (7 g, 40.8 mmol),(4-chloro-2-fluorophenyl)boronic acid (7.11 g, 40.8 mmol) and cesiumcarbonate (26.6 g, 82 mmol) in a mixture of dioxane (60 mL) and water (8mL) purged with nitrogen gas for 5 min, was added Pd(PPh₃)₄ (2.83 g,2.448 mmol) and the resultant mixture was heated at 85° C. for 15 h.Water (30 mL) was added and the mixture was extracted with EtOAc (1×50mL). The organic layer was washed with water (1×30 mL) and brine (1×30mL), dried over sodium sulfate and concentrated under reduced pressure.The residue was purified via silica gel column (30% EtOAc in hexane) togive methyl 4-(4-chloro-2-fluorophenyl)nicotinate (5 g, 18.82 mmol, 40%yield). LCMS (ESI) m/e 266.7 [(M+H)⁺, calcd for C₁₃H₁₀ClFNO₂ 266.0];LCMS retention time (Method C): t_(R)=1.73 min.

Part C. 4-(4-Chloro-2-fluorophenyl)nicotinic acid

To a solution of methyl 4-(4-chloro-2-fluorophenyl)nicotinate (1 g, 3.76mmol) in MeOH (10 mL) and water (10 mL) was added NaOH (0.602 g, 15.06mmol) and the solution stirred at room temperature for 2 h. The volatileorganic solvent was evaporated under reduced pressure. The reactionmixture was cooled to 0° C. and acidified with 50% aqueous HCl. Theprecipitated so formed was collected by vacuum filtration to yield4-(4-chloro-2-fluorophenyl)nicotinic acid (0.3 g, 1.192 mmol, 30% crudeyield) as an off-white solid which was carried directly into the nextstep. ¹H NMR (400 MHz, CD₃OD) δ 9.12 (s, 1H), 8.78 (d, J=5.20 Hz, 1H),7.29-7.48 (m, 4H).

Part D. 8-chloro-5H-chromeno[3,4-c]pyridin-5-one

To a solution of 4-(4-chloro-2-fluorophenyl)nicotinic acid (0.3 g, 1.192mmol) in anhydrous DMSO (1 mL) was added Cs₂CO₃ (0.388 g, 1.192 mmol)and the mixture was subjected to microwave heating for 2 h at 60° C. Thereaction mixture was diluted with water and extracted with ethyl acetate(2×15 mL). The combined organic extracts were washed with water (1×15mL) and brine (1×15 mL), dried over sodium sulfate and concentratedunder reduced pressure to afford8-chloro-5H-chromeno[3,4-c]pyridin-5-one (0.2 g, 0.863 mmol, 72% yieldover 2 steps). ¹H NMR (400 MHz, CDCl₃) δ 9.57 (d, J=0.40 Hz, 1H), 8.98(d, J=5.60 Hz, 1H), 8.01 (d, J=8.80 Hz, 1H), 7.88 (q, J=0.40 Hz, 1H),7.44 (d, J=2.00 Hz, 1H), 7.39 (q, J=2.00 Hz, 1H); LCMS (ESI) m/e 232.6[(M+H)⁺, calcd for C₁₂H₂ClNO₂ 232.0]; LCMS retention time (Method D):t_(R)=0.81 min.

Part E.tert-butyl(4-methyl-1-((5-oxo-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate

Tert-butyl(4-methyl-1-((5-oxo-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamatewas prepared in an analogous fashion to Example 8, Part C to give thetitled product (0.18 g, 0.436 mmol, 50% yield). ¹H NMR (400 MHz, CD₃OD)δ 9.36 (s, 1H), 8.85 (d, J=5.6 Hz, 1H), 8.22 (d, J=8.8 Hz, 1H), 8.15 (d,J=5.6 Hz, 1H), 7.08 (m, 1H), 7.01 (d, J=2.4 Hz, 1H), 4.04-4.07 (m, 3H),1.48 (m, 1H), 1.46 (s, 9H), 1.36 (m, 2H), 0.94-1.01 (m, 6H); LCMS (ESI)m/e 413 [(M+H)⁺, calcd for C₂₃H₂₉N₂O₅ 413.2]; LCMS retention time(Method D): t_(R)=0.96 min.

Part F (S)-8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-5-one

The deprotection oftert-butyl(4-methyl-1-((5-oxo-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamatewas carried out in an analogous fashion to Example 8, Part D to give(S)-8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-5-one (0.065g, 0.208 mmol, 44% yield) as a white solid.

¹H NMR (400 MHz, MeOD) δ 9.37 (s, 1H), 8.80 (d, J=10.6 Hz, 1H), 8.28 (d,J=8.9 Hz, 1H), 8.22 (d, J=5.6 Hz, 1H), 7.17 (m, 1H), 7.09 (d, J=2.4 Hz,1H), 4.23 (m, 1H), 4.07 (m, 1H), 3.50 (m, 1H), 1.84 (m, 1H), 1.57 (m,2H), 1.17 (m, 6H); LCMS (ESI) m/e 313.2 [(M+H)⁺, calcd for C₁₈H₂₁N₂O₃313.2]; LC/MS retention time (Method C): t_(R)=1.25 min; HPLC retentiontime (method A): t_(R)=4.90 min; HPLC retention time (method B):t_(R)=5.47 min.

Example 12(S)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-4-yl)acetamide

Part A. tert-Butyl 4-chloropyridin-2-ylcarbamate

A stirred solution of 4-chloropicolinic acid (0.2 g, 1.269 mmol), DPPA(0.351 g, 1.269 mmol) and TEA (0.354 mL, 2.54 mmol) in tert-butanol (15mL) was purged with nitrogen for 5 min and the reaction mixture washeated at 100° C. for 12 h. The mixture was cooled to room temperatureand the volatiles were removed under reduced pressure. The reactionmixture was diluted with water (15 mL) and extracted with ethyl acetate(3×15 mL). The combined organic extracts were washed with brine (1×15mL), dried over sodium sulfate and concentrated under reduced pressure.The residue was purified by silica gel chromatography (15% Ethyl acetatein hexane) to yield tert-butyl(4-chloropyridin-2-yl)carbamate (0.17 g,0.743 mmol, 59% yield) as a yellow solid. ¹H NMR (400 MHz, CD₃OD) δ 8.23(d, J=5.2 Hz, 1H), 7.88 (d, J=5.2 Hz, 1H), 7.16 (m, 1H), 1.48 (s, 9H).

Part B. tert-Butyl 4-chloro-3-formylpyridin-2-ylcarbamate

To a stirred solution of tert-butyl(4-chloropyridin-2-yl)carbamate (1.00g, 4.37 mmol) in THF (30 mL) cooled to −78° C. was added n-butyllithium(2.55 M in hexane, 4.1 mL, 10.06 mmol) dropwise. After complete additionthe solution was stirred at −78° C. for 1 h. DMF (1.591 mL, 20.55 mmol)was added dropwise and the resultant solution stirred at −78° C. for anadditional 1 h. The reaction mixture was then quenched by addition ofsaturated aqueous ammonium chloride solution (20 mL) and extracted withethyl acetate (2×25 mL). The combined organic extracts were washed withbrine (1×20 mL), dried over sodium sulfate and concentrated underreduced pressure. The crude residue was purified via neutral alumina gelchromatography (ethyl acetate/hexanes) to yieldtert-butyl(4-chloro-3-formylpyridin-2-yl)carbamate (530 mg, 2.07 mmol,27% yield) as a yellow solid. ¹H NMR (400 MHz, CDCl₃) δ 10.73 (s, 1H),10.55 (s, 1H), 8.52 (d, J=5.3 Hz, 1H), 7.06 (d, J=5.3 Hz, 1H), 1.56 (s,9H); LCMS (ESI) m/e 255.2 [(M−H)⁻, calcd for C₁₁H₁₂ClN₂O₃ 255.0]; LCMSretention time (Method C): t_(R)=1.73 min.

Part C. tert-Butyl4-(4-chloro-2-fluorophenyl)-3-formylpyridin-2-ylcarbamate

To a stirred suspension oftert-butyl(4-bromo-3-formylpyridin-2-yl)carbamate (100 mg, 0.332 mmol),(4-chloro-2-fluorophenyl)boronic acid (57.9 mg, 0.332 mmol) and cesiumcarbonate (216 mg, 0.664 mmol) in THF (50 mL) and water (8 ml) was addedPd(PPh₃)₄ (19.19 mg, 0.017 mmol) and the reaction mixture was heated to85° C. overnight. The reaction mixture was cooled to room temperature,diluted with water (30 mL) and extracted with ethyl acetate (2×25 mL).The combined organic extracts were washed with brine (1×25 mL), driedover sodium sulfate and concentrated under reduced pressure. The cruderesidue was purified via silica gel chromatography (ethylacetate/hexanes) to afford tert-butyl4-(4-chloro-2-fluorophenyl)-3-formylpyridin-2-ylcarbamate (60 mg, 0.171mmol, 35% yield). LCMS (ESI) m/e 349.2 [(M−H)⁻, calcd for C₁₇H₁₅ClFN₂O₃349.1]; LC/MS retention time (Method C): t_(R)=2.05 min.

Part D. 2-Amino-4-(4-chloro-2-fluorophenyl)nicotinaldehyde

To a stirred solution oftert-butyl(4-(4-chloro-2-fluorophenyl)-3-formylpyridin-2-yl)carbamate(0.9 g, 2.57 mmol) in CH₂Cl₂ (15 mL) was added TFA (3.95 mL, 51.3 mmol)and the reaction mixture was stirred at room temperature for 3 h. Thereaction was quenched by addition of saturated aqueous sodiumbicarbonate solution (15 mL) and extracted with CH₂Cl₂ (2×15 mL). Thecombined organic extracts were washed with brine (1×15 mL), dried oversodium sulfate and concentrated under reduced pressure. The crude2-amino-4-(4-chloro-2-fluorophenyl)nicotinaldehyde (0.6 g, 2.40 mmol,41% yield) was carried into the next step without further purification.LCMS (ESI) m/e 251.0 [(M+H)⁺, calcd for C₁₂H₉ClFN₂O 251.0]; LC/MSretention time (Method C): t_(R)=1.67 min.

Part E. (2-amino-4-(4-chloro-2-fluorophenyl)pyridin-3-yl)methanol

To a stirred solution of2-amino-4-(4-chloro-2-fluorophenyl)nicotinaldehyde (50 mg, 0.199 mmol)in MeOH (2 mL) and THF (5 mL) was added sodium borohydride (9.06 mg,0.239 mmol) then the solution was stirred for 1 h. The volatile organicswere removed under reduced pressure and the residue was quenched byaddition of saturated aqueous ammonium chloride solution (10 mL). Thereaction mixture was extracted with CH₂Cl₂ (2×10 mL). The combinedorganic extracts were washed with brine (1×10 mL), dried over sodiumsulfate and concentrated under reduced pressure to yield(2-amino-4-(4-chloro-2-fluorophenyl)pyridin-3-yl)methanol (50 mg, 0.198mmol, 21% yield for two steps). LCMS (ESI) m/e 253 [(M+H)⁺, calcd forC₁₂H₁₁ClFN₂O 253.0]; LC/MS retention time (Method C): t_(R)=1.48 min.

Part F. N-(8-chloro-5H-chromeno[3,4-c]pyridin-4-yl)acetamide

To a stirred solution of 8-chloro-5H-chromeno[3,4-c]pyridin-4-amine(0.08 g, 0.344 mmol) in pyridine (5 mL) at 0° C. was added acetylchloride (0.024 mL, 0.344 mmol) and the solution was stirred for 2 h.The volatile organics were removed under reduced pressure and theresidue was diluted with water (5 mL). The reaction mixture wasextracted with CH₂Cl₂ (2×15 mL). The combined organic extracts werewashed with brine (1×10 mL), dried over sodium sulfate and concentratedunder reduced pressure. The crude residue was taken to the next stepwithout purification. LCMS (ESI) m/e 273 [(M)⁻, calcd for C₁₄H₁₀ClN₂O₂273.1]; LC/MS retention time (Method C): t_(R)=1.89 min.

Part G.(S)—N-(8-((2-(1,3-dioxoisoindolin-2-yl)-4-methylpentyl)oxy)-5H-chromeno[3,4-d]pyridin-4-yl)acetamide

To a stirred solution ofN-(8-chloro-5H-chromeno[3,4-c]pyridin-4-yl)acetamide (47 mg, 0.171mmol), (S)-2-(1-hydroxy-4-methylpentan-2-yl)isoindoline-1,3-dione (127mg, 0.513 mmol), 2-di-tert-butylphosphino-2,4,6-triisopropylbiphenyl(43.6 mg, 0.103 mmol), and cesium carbonate (84 mg, 0.257 mmol) intoluene (25 mL) at room temperature was added palladium (II) acetate(11.52 mg, 0.051 mmol). Nitrogen was bubbled through the solution for 5min, and the mixture heated at 80° C. for 14 h. The reaction mixture wascooled to room temperature and diluted with ethyl acetate (30 mL) thenfiltered through celite. Water (30 mL) was added and the organic layerwas separated and washed with brine (1×25 mL), dried with sodium sulfateand concentrated under reduced pressure. The residue was used withoutfurther purification in the next step. LCMS (ESI) m/e 486.2 [(M+H)⁺,calcd for C₂₈H₂₈N₃O₅ 486.2]; LC/MS retention time (Method C): t_(R)=2.07min.

Part H.(S)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-4-yl)acetamide

To a stirred solution of(S)-tert-butyl(1-((4-acetamido-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(150 mg, 0.329 mmol) in CH₂Cl₂ (10 mL) at room temperature was added TFA(0.025 mL, 0.329 mmol) and the solution was stirred at room temperaturefor 3 h. The solution was concentrated under reduced pressure and thesample was purified by preparative HPLC (0.1% TFA in water and methanol)yielding(S)—N-(8-((2-amino-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-4-yl)acetamide(40 mg, 0.113 mmol, 33% yield for three steps) as an off-white solid. ¹HNMR (400 MHz, CD₃OD) δ 8.34 (d, J=5.3 Hz, 1H), 7.81 (d, J=8.7 Hz, 1H),7.58 (d, J=5.4 Hz, 1H), 6.77 (m, 1H), 6.63 (d, J=2.4 Hz, 1H), 4.94 (s,2H), 4.03 (m, 1H), 3.85 (m, 1H), 3.33 (m, 1H), 2.21 (s, 3H), 1.81 (m,1H), 1.43 (m, 2H), 0.99 (m, 6H); LCMS (ESI) m/e 356.2 [(M+H)⁺, calcd forC₂₀H₂₆N₃O₃ 356.2]; LC/MS retention time (Method C): t_(R)=1.26 min; HPLCretention time (method A): t_(R)=8.02 min; HPLC retention time (methodB): t_(R)=9.08 min.

Example 13(S)-8-((2-amino-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-4-amine

To a stirred solution of(S)—N-(8-((2-amino-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-4-yl)acetamide(20 mg, 0.056 mmol) (prepared as in Example 12, Part H) in a mixture ofethanol (10 mL) and water (2 mL) was added KOH (31.6 mg, 0.563 mmol) andthe reaction was heated at 70° C. for 14 h. After completion of thereaction, the volatile organic solvent was removed under reducedpressure, water (20 mL) was added and the solution extracted withdichloromethane (2×20 mL). The combined organic extracts were washedwith water (1×20 mL), dried over sodium sulfate and concentrated underreduced pressure to obtain(S)-8-((2-amino-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-4-amine(2.31 mg, 7.15 umol, 13% yield) as an off-white solid. ¹H NMR (400 MHz,MeOD) δ 7.90 (d, J=5.6 Hz, 1H), 7.69 (d, J=8.7 Hz, 1H), 6.98 (d, J=5.6Hz, 1H), 6.72 (m, 1H), 6.6 (d, J=2.5 Hz, 1H), 5.07 (s, 2H), 4.10 (m,1H), 3.92 (m, 1H), 3.40 (m, 1H), 1.82 (m, 1H), 1.49 (m, 2H), 1.01 (m,6H); LCMS (ESI) m/e 314.2 [(M+H)⁺, calcd for C₁₈H₂₄N₃O₂ 314.2]; LC/MSretention time (Method C): t_(R)=1.21 min; HPLC retention time (methodA): t_(R)=7.52 min; HPLC retention time (method B): t_(R)=8.68 min.

Example 14(S)-1-(9-bromo-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine

Part A. (S)-tert-butyl1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

To 8-chloro-5H-chromeno[3,4-c]pyridine (0.489 g, 2.247 mmol) (preparedas in Example 5, Part D),(S)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate (1.474 g, 6.79mmol),di-tert-butyl(2′,4′,6′-triisopropyl-[1,1′-biphenyl]-2-yl)phosphine(0.572 g, 1.348 mmol), palladium (II) acetate (0.151 g, 0.674 mmol) andcesium carbonate (1.098 g, 3.37 mmol) was added toluene (4 mL). Nitrogengas was bubbled through the mixture for 5 min and the mixture heated at80° C. for 15 h. The reaction mixture was cooled to room temperature andfiltered through a bed of celite. Water (10 mL) was added to thefiltrate and the product was extracted with ethyl acetate (3×15 mL). Thecombined organic extracts were washed with brine (1×10 mL), dried withsodium sulfate and concentrated under reduced pressure. The residue soobtained was purified by preparative TLC using (50% ethyl acetate in petether) to affordtert-butyl(1-((5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(0.4 g, 1.00 mmol, 45% yield) as a semi solid. LCMS (ESI) m/e 399.2[(M+H)⁺, calcd for C₂₃H₃₁N₂O₄ 399.5]; LC/MS retention time (Method C):t_(R)=2.16 min.

Part B. (S)-tert-butyl1-(9-bromo-5H-chromeno[3,4-e]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

A solution oftert-butyl(1-((5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(0.072 g, 0.181 mmol) in acetonitrile (5 mL) cooled to 0° C. and stirredfor 2 min. NBS (0.029 g, 0.163 mmol) was added in single portion and thereaction mixture stirred at 0° C. for 2 h. The solvent was removed underreduced pressure and water 10 mL) was added. The product was extractedwith ethyl acetate (3×15 mL). The combined organic extracts were washedwith water (1×20 mL) dried over sodium sulfate and concentrated underreduced pressure. The residue was purified via preparative TLC (40%EtOAc:pet ether) to obtain (S)-tert-butyl1-(9-bromo-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate(30 mg, 0.063 mmol, 35% yield). ¹H NMR (400 MHz, CD₃OD) δ 8.48 (d, J=5.4Hz, 1H), 8.38 (s, 1H), 8.07 (s, 1H), 7.68 (d, J=5.4 Hz, 1H), 6.73 (s,1H), 5.21 (s, 2H), 4.02-3.98 (m, 3H), 1.92-1.71 (m, 1H), 1.56-1.52 (m,2H), 0.97 (t, J=6.8 Hz, 6H).

Part C.(S)-1-(9-bromo-5H-chromeno[3,4-e]pyridin-8-yloxy)-4-methylpentan-2-amine

To a solution oftert-butyl(1-((9-bromo-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(0.045 g, 0.094 mmol) in dichloromethane (4 mL) cooled to 0° C. wasadded hydrogen chloride, 2M in diethyl ether (6 mL, 0.094 mmol) slowlyover a period of 5 min. The reaction mixture was stirred at 0° C. for 5min, then at room temperature for 2 h. The solvents were removed byconcentration under reduced pressure. The crude product was taken up inwater (10 mL) and washed with diethyl ether (3×10 mL). The aqueous layerwas concentrated and purified by reverse phase HPLC (0.1% TFA in waterand acetonitrile) to yield149-bromo-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine(0.016 g, 0.042 mmol, 45% yield) as a yellow solid. ¹H NMR (400 MHz,CD₃OD) δ 8.68 (bs, 2H), 8.35 (s, 1H), 8.26 (s, 1H), 6.90 (s, 1H), 5.39(s, 2H), 4.41 (m, 1H), 4.27 (m, 1H), 3.76 (m, 1H), 1.82 (m, 2H), 1.69(m, 1H), 1.05 (m, 6H). LCMS (ESI) m/e 377.0 [(M+H)⁺, calcd forC₁₈H₂₂BrN₂O₂ 377.1]; LC/MS retention time (Method D): t_(R)=1.25 min;HPLC retention time (method A): t_(R)=8.59 min; HPLC retention time(method B): t_(R)=10.33 min.

Example 158-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-4-amine

Part A. 1-(2-amino-4-(4-chloro-2-fluorophenyl)pyridin-3-yl)ethanol

To a stirred solution of2-amino-4-(4-chloro-2-fluorophenyl)nicotinaldehyde (0.2 g, 0.798 mmol)(prepared as described in Example 12, Part D) in THF (15 mL) was addedmethylmagnesium bromide (3.0 M in THF) (0.82 mL, 2.394 mmol) at −60° C.and the reaction was stirred for 30 min. The reaction was quenched withsaturated ammonium chloride solution, extracted with ethyl acetate (2×10mL). The combined organic layers were washed with brine (1×10 mL), driedover sodium sulphate, and concentrated under reduced pressure to give1-(2-amino-4-(4-chloro-2-fluorophenyl)pyridin-3-yl)ethanol (0.2 g, 0.691mmol, 87% yield). LCMS (ESI) m/e 267.0 [(M+H)⁺, calcd for C₁₃H₁₃ClFN₂O267.1]; LC/MS retention time (Method D): t_(R)=1.36 min.

Part B. 8-chloro-5-methyl-5H-chromeno[3,4-c]pyridin-4-amine

Prepared as described in Example 5, Part D using1-(2-amino-4-(4-chloro-2-fluorophenyl)pyridin-3-yl)ethanol to afford8-chloro-5-methyl-5H-chromeno[3,4-c]pyridin-4-amine (0.15 g, 0.557 mmol,74% yield). LCMS (ESI) m/e 247.0 [(M+H)⁺, calcd for C₁₃H₁₂ClN₂O 247.05];LC/MS retention time (Method D): t_(R)=1.52 min.

Part C. N-(8-chloro-5-methyl-5H-chromeno[3,4-d]pyridin-4-yl)acetamide

Prepared as described in Example 12, Part F using8-chloro-5-methyl-5H-chromeno[3,4-c]pyridin-4-amine to affordN-(8-chloro-5-methyl-5H-chromeno[3,4-c]pyridin-4-yl)acetamide (0.142 g,0.398 mmol, 66% yield). LCMS (ESI) m/e 289.0 [(M+H)⁺, calcd forC₁₅H₁₄ClN₂O₂ 289.1]; LC/MS retention time (Method B): t_(R)=1.62 min.

Part D. (S)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate

To a stirred solution of (S)-2-amino-4-methylpentan-1-ol (5 g, 42.7mmol) in tetrahydrofuran (100 mL) at rt was added BOC₂O (9.91 mL, 42.7mmol) dropwise and the reaction was stirred at rt for 5 h. After thecompletion of reaction, solvent was removed under reduced pressure toyield (S)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate (6.3 g,29.0 mmol, 68% yield) as a colorless oil. ¹H NMR (400 MHz, DMSO-d₆) δ6.42 (d, J=8.8 Hz, 1H), 4.55 (m, 1H), 3.32 (m, 1H), 3.27 (m, 1H), 3.17(m, 1H), 1.47 (m, 1H), 1.37 (s, 9H), 1.22 (m, 2H), 0.85 (m, 6H).

Part E.tert-butyl((2S)-1-((4-acetamido-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate

Prepared as described in Example 8, Part C using(S)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate andN-(8-chloro-5-methyl-5H-chromeno[3,4-c]pyridin-4-yl)acetamide to affordtert-butyl((2S)-1-((4-acetamido-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(0.6 g, 0.882 mmol, 51% yield) as a yellow solid. LCMS (ESI) m/e 470.2[(M+H)⁺, calcd for C₂₆H₃₆N₃O₅ 470.3]; LC/MS retention time (Method C):t_(R)=1.89 min.

Part F.N-(8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-4-yl)acetamide

To a stirred solution oftert-butyl((2S)-1-((4-acetamido-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(0.15 g, 0.319 mmol) in dichloromethane (25 mL) at room temperature wasadded TFA (0.246 mL, 3.19 mmol) and the mixture stirred for 12 h. Aftercompletion of reaction, the solvent was removed under reduced pressureto affordN-(8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-4-yl)acetamide(0.18 g, 0.281 mmol, 58% yield) as a brown oil. The product was carriedforward into the next step without further purification. LCMS (ESI) m/e370.2 [(M+H)⁺, calcd for C₂₁H₂₈N₃O₃ 370.2]; LC/MS retention time (MethodC): t_(R)=1.14 min.

Part G.8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-4-amine

Prepared as described in Example 13 usingN-(8-((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-4-yl)acetamideto afford8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-4-amine(15 mg, 0.045 mmol, 9% yield) as a yellow solid. ¹H NMR (400 MHz, MeOD)δ 7.95 (m, 2H), 7.35 (m, 1H), 6.92 (m, 1H), 6.74 (s, 1H), 5.66 (m, 1H),4.35 (m, 1H), 4.15 (m, 1H), 3.74 (m, 1H), 1.82-1.72 (m, 3H), 1.52 (m,3H), 1.04 (m, 6H); LCMS (ESI) m/e 328.2 [(M+H)⁺, calcd for C₁₉H₂₆N₃O₂328.2]; LC/MS retention time (Method D): t_(R)=1.25 min; HPLC retentiontime (method A): t_(R)=8.78 min; HPLC retention time (method C):t_(R)=12.78 min.

Example 16(S)-1-((1-fluoro-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine

Part A. 4-chloro-5-fluoronicotinic acid

N-Butyllithium, 1.6 M in hexanes (9.50 mL, 15.21 mmol) was added to THF(20 mL) and cooled to −78° C. To this solution was addeddiisopropylamine (2.167 mL, 15.21 mmol) followed by4-chloro-3-fluoropyridine (2 g, 15.21 mmol) and the solution stirred for6 h at −78° C. The reaction mixture was then poured on to crushed dryice and stirred until the reaction mixture warmed to room temperature.The reaction was quenched by addition of aqueous ammonium chloridesolution and acidified to pH=2 using conc. HCl and extracted with ethylacetate (3×10 mL). The combined organic layers were washed with brine(10 mL), dried over sodium sulphate and concentrated under reducedpressure to afford the 4-chloro-5-fluoronicotinic acid (1.7 g, 9.68mmol, 64% yield) as a pale yellow solid. LCMS (ESI) m/e 175.9 [(M+H)⁺,calcd for C₆H₄ClFNO₂ 176.0]; LC/MS retention time (Method F): t_(R)=0.57min.

Part B. methyl 4-chloro-5-fluoronicotinate

A solution of 4-chloro-5-fluoronicotinic acid (1.7 g, 9.68 mmol) inacetonitrile (18 mL) was cooled to 0° C. To this solution was added DBU(3.65 mL, 24.21 mmol) dropwise and the resultant solution stirred for 30min. Iodomethane (3.03 mL, 48.4 mmol) was added dropwise and stirred atroom temperature for 12 h. The volatiles were removed completely underreduced pressure and the residue purified via silica gel chromatographyusing a gradient of ethyl acetate in hexane to afford methyl4-chloro-5-fluoronicotinate (1.2 g, 6.33 mmol, 65% yield) as a yellowsolid. LCMS (ESI) m/e 190.0 [(M+H)⁺, calcd for C₇H₆ClFNO₂ 190.0]; LC/MSretention time (Method F): t_(R)=0.77 min.

Part C. Methyl 4-(4-chloro-2-fluorophenyl)-5-fluoronicotinate

To a solution of 4-chloro-5-fluoronicotinate (1.2 g, 6.33 mmol) in1,4-dioxane (12 mL) and water (0.5 mL) was added(4-chloro-2-fluorophenyl)boronic acid (1.214 g, 6.96 mmol) and potassiumphosphate, dibasic (2.205 g, 12.66 mmol). To this mixture, PdCl₂(dppf)(0.371 g, 0.506 mmol) was added and the solution purged with N₂ for 10min then heated to 80° C. for 12 h. The mixture was cooled to roomtemperature and water (25 mL) was added. The solution was extracted withethyl acetate (3×25 mL). The combined organic layers were washed withbrine (25 mL) and concentrated under reduced pressure to afford theresidue which was purified by silica gel column using a gradient ofethyl acetate in hexanes to afford methyl4-(4-chloro-2-fluorophenyl)-5-fluoronicotinate (900 mg, 3.17 mmol, 50%yield) as a yellow solid. LCMS (ESI) m/e 284.0 [(M+H)⁺, calcd forC₁₃H₉ClF₂NO₂ 284.0]; LC/MS retention time (Method F): t_(R)=1.01 min.

Part D. (4-(4-chloro-2-fluorophenyl)-5-fluoropyridin-3-yl)methanol

To a solution of 4-(4-chloro-2-fluorophenyl)-5-fluoronicotinate (300 mg,1.058 mmol) in tetrahydrofuran (7 mL) cooled to 0° C. was added LAH(0.441 mL, 1.058 mmol) in THF dropwise and the solution was stirred for30 min. The reaction was then warmed to room temperature and stirred for12 h. The reaction was quenched with saturated aqueous ammonium chloride(5 mL) and extracted with ethyl acetate (2×5 mL). The combined organiclayers were dried over sodium sulphate and concentrated under reducedpressure to afford(4-(4-chloro-2-fluorophenyl)-5-fluoropyridin-3-yl)methanol (200 mg,0.782 mmol, 74% yield) as a pale brown oil. LCMS (ESI) m/e 255.9[(M+H)⁺, calcd for C₁₂H₉ClF₂NO 256.0]; LC/MS retention time (Method F):t_(R)=0.89 min.

Part E. 8-chloro-1-fluoro-5H-chromeno[3,4-d]pyridine

Prepared as described in Example 8, Part B using(4-(4-chloro-2-fluorophenyl)-5-fluoropyridin-3-yl)methanol to afford8-chloro-1-fluoro-5H-chromeno[3,4-c]pyridine (35 mg, 0.149 mmol, 19%yield) as a white solid. LCMS (ESI) m/e 235.9 [(M+H)⁺, calcd forC₁₂H₈ClFNO 236.0]; LC/MS retention time (Method F): t_(R)=0.92 min.

Part F.(S)-tert-butyl(1-((1-fluoro-5H-chromeno[3,4-d]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate

Prepared as described in Example 8, Part C using8-chloro-1-fluoro-5H-chromeno[3,4-c]pyridine to afford(S)-tert-butyl(1-((1-fluoro-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(35 mg, 0.084 mmol, 66% yield) as a pale yellow solid. LCMS (ESI) m/e417.1 [(M+H)⁺, calcd for C₂₃H₃₀FN₂O₄ 417.2]; LC/MS retention time(Method F): t_(R)=1.00 min.

Part G.(S)-1-((1-fluoro-5H-chromeno[3,4-e]pyridin-8-yl)oxy)-4-methylpentan-2-amine

Prepared as described Example 8, Part D using(S)-tert-butyl(1-((1-fluoro-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamateto afford(S)-1-((1-fluoro-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine,2 TFA (12.47 mg, 0.022 mmol, 26% yield) as a white solid. ¹H NMR (400MHz, MeOD) δ 9.46 (d, J=3.2 Hz, 1H), 8.29 (s, 1H), 8.05 (d, J=9.2 Hz,1H), 6.87 (m, 1H), 6.77 (d, J=2.4 Hz, 1H), 5.2 (s, 2H), 4.33 (m, 1H),4.12 (m, 1H), 3.69 (m, 1H), 1.85-1.71 (m, 3H), 1.1 (m, 6H). LCMS (ESI)m/e 317.0 [(M+H)⁺, calcd for C₁₈H₂₂FN₂O₂ 317.2]; LC/MS retention time(Method F): t_(R)=0.62 min; HPLC retention time (method A): t_(R)=10.68min; HPLC retention time (method B): t_(R)=11.50 min.

Example 171-(5H-chromeno[3,4-c]pyridin-8-yloxy)-5,5,5-trifluoropentan-2-amine

Part A. tert-butyl 2-(diphenylmethyleneamino)-5,5,5-trifluoropentanoate

To a stirred solution of tert-butyl 2-((diphenylmethylene)amino)acetate(1 g, 3.39 mmol) in THF (20 ml) cooled to −78° C. under nitrogenatmosphere was added LDA, 2M in THF/heptane/ethylbenzene (2.54 ml, 5.08mmol) dropwise for 30 mins. To this mixture was then added3,3,3-trifluoropropyl trifluoromethanesulfonate (1.083 g, 4.40 mmol).The reaction was gradually warmed to rt and stirred for 4 h. Thereaction mixture was quenched by addition of saturated aqueous ammoniumchloride at 0° C. The reaction mixture was then extracted with ethylacetate (3×10 mL). The combined organic extracts were washed with waterand brine, dried over sodium sulfate and then concentrated under reducedpressure. The crude product was purified by silica gel columnchromatography using 2% ethyl acetate in hexane to afford tert-butyl2-((diphenylmethylene)amino)-5,5,5-trifluoropentanoate (800 mg, 2.02mmol, 60% yield) as a yellow oil. LCMS (ESI) m/e 391.9 [(M+H)⁺, calcdfor C₂₂H₂₄F₃NO₂, 392.2]; LC/MS retention time (method E): t_(R)=2.49min.

Part B. (S)-2-amino-5,5,5-trifluoropentanoic acid (Hydrochloride salt)

A stirred solution of tert-butyl2-((diphenylmethylene)amino)-5,5,5-trifluoropentanoate (800 mg, 2.023mmol) in 50% aqueous hydrochloric acid (0.123 mL, 2.023 mmol) was heatedto reflux at 100° C. for 8 h. The reaction mixture was cooled to rt andwashed with ethyl acetate (10 mL). The aqueous layer was concentratedunder reduced pressure to afford 2-amino-5,5,5-trifluoropentanoic acidhydrochloride (400 mg, 1.82 mmol, 90% yield) as white solid. LCMS (ESI)m/e 171.7 [(M+H)⁺, calcd for C₅H₇F₃O₂, 172.1]; LC/MS retention time(method H): t_(R)=0.80 min.

Part C. (S)-2-(tert-butoxycarbonylamino)-5,5,5-trifluoropentanoic acid

To a stirred solution of 2-amino-5,5,5-trifluoropentanoic acidhydrochloride (400 mg, 1.503 mmol) in THF (8 mL) and water (8 mL) wasadded K₂CO₃ (831 mg, 6.01 mmol) at rt and the solution was stirred for10 min. To this mixture was added BOC₂O (656 mg, 3.01 mmol). Thereaction mixture was stirred for 8 h at rt. The reaction mixture wasconcentrated under reduced pressure. The aq. layer was washed with ethylacetate (3×5 mL). The aqueous layer was acidified with saturated citricacid solution (5 mL) and then extracted with ethyl acetate (3×8 mL). Thecombined organic layers were washed with water (3×5 mL) followed bybrine (10 mL), dried over sodium sulfate and concentrated under reducedpressure to afford2-((tert-butoxycarbonyl)amino)-5,5,5-trifluoropentanoic acid (500 mg,1.84 mmol) quantitatively as a colorless oil. The crude material wastaken as such to the next step without further purification. ¹H NMR (400MHz, CDCl₃) δ 5.04 (s, 1H), 4.38 (s, 1H), 2.15-2.28 (m, 2H), 1.91-1.95(m, 2H), 1.46 (s, 9H).

Part D. tert-butyl 5,5,5-trifluoro-1-hydroxypentan-2-ylcarbamate

To a stirred solution of2-((tert-butoxycarbonyl)amino)-5,5,5-trifluoropentanoic acid (500 mg,1.843 mmol) in THF (15 ml) cooled to −10° C. under a nitrogen atmospherewas added N-methylmorpholine (0.223 ml, 2.028 mmol) followed by isobutylchloroformate (0.266 ml, 2.028 mmol) dropwise and stirred for 30 min.The reaction mixture was filtered. The filtrate was added to sodiumborohydride (147 mg, 3.87 mmol) in water (10 mL) and stirred for 5 min.The mixture was diluted with ethyl acetate (10 mL). The organic layerwas separated and washed with brine (2×10 mL), dried (Na₂SO₄) andevaporated under reduced pressure to affordtert-butyl(5,5,5-trifluoro-1-hydroxypentan-2-yl)carbamate (400 mg, 1.55mmol, 84% yield) as a white solid which was taken to the next stepwithout any purification. ¹H NMR (400 MHz, CDCl₃) δ 3.73-3.59 (m, 3H),2.24-2.16 (m, 2H), 1.87-1.69 (m, 2H), 1.44 (s, 9H).

Part E. tert-butyl1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-5,5,5-trifluoropentan-2-ylcarbamate

Prepared as described in Example 8, Part C using8-chloro-5H-chromeno[3,4-c]pyridine to affordtert-butyl(1-((5H-chromeno[3,4-c]pyridin-8-yl)oxy)-5,5,5-trifluoropentan-2-yl)carbamate(25 mg, 9.12 μmol, 4% yield) as a brownish solid. LCMS (ESI) m/e 439.2[(M+H)⁺, calcd for C₂₂H₂₆F₃N₂O₄ , 439.2] LC/MS retention time (methodC): t _(R)=2.04 min.

Part F.1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-5,5,5-trifluoropentan-2-amine

Prepared as described in Example 8, Part D usingtert-butyl(1-((5H-chromeno[3,4-c]pyridin-8-yl)oxy)-5,5,5-trifluoropentan-2-yl)carbamateto afford1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-5,5,5-trifluoropentan-2-amine (15mg, 0.041 mmol, 18% yield) as a yellow oil. ¹H NMR (400 MHz, MeOD) δ8.68 (m, 2H), 8.27 (d, J=6.4 Hz, 1H), 8.11 (d, J=8.8 Hz, 1H), 6.97 (m,1H), 6.83 (d, J=2.4 Hz, 1H), 5.39 (s, 2H), 4.39 (m, 1H), 4.26 (m, 1H),3.78 (m, 1H), 2.5-2.43 (m, 2H), 2.15-2.07 (m, 2H); LCMS (ESI) m/e 339.1[(M+H)⁺, calcd for C₁₇H₁₈F₃N₂O₂ 339.1]; LC/MS retention time (Method E):t_(R)=1.76 min; HPLC retention time (method A): t_(R)=7.46 min; HPLCretention time (method B): t_(R)=8.75 min.

Example 18(S)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Part A. 4-chloropyridin-2-amine

To a stirred solution of 4-chloropyridin-2-amine (8 g, 62.2 mmol) inacetonitrile (600 mL) at rt was added NBS (11.08 g, 62.2 mmol) inportions and the reaction was stirred for 14 h. The reaction mixture wasconcentrated under reduced pressure. The residue was reconstituted inethyl acetate and water. The organics were extracted with ethyl acetate(3×50 mL). The combined organic layers were washed with water (100 mL),brine (100 mL), and dried over sodium sulphate. The organics wereconcentrated under reduced pressure to afford5-bromo-4-chloropyridin-2-amine as yellow solid (13 g, 99% yield) thatwas used without further purification in the next step. LCMS (ESI) m/e207.0 [(M+H)⁺, calcd for C₅H₅BrClN₂ 206.9]; LC/MS retention time (methodB): t_(R)=0.8 min; ¹H NMR (400 MHz, CDCl₃) δ 8.17 (s, 1H), 6.63 (s, 1H),4.59 (s, 2H).

Part B. N-(5-bromo-4-chloropyridin-2-yl)acetamide

To a stirred solution of 5-bromo-4-chloropyridin-2-amine (11.6 g, 55.9mmol) in pyridine (100 mL) at 0° C. was added acetyl chloride (3.98 mL,55.9 mmol) and the reaction was stirred at rt for 3 hours. The reactionwas quenched with cold water. The reaction mixture was concentratedunder reduced pressure. The residue was reconstituted in ethyl acetateand water. The organics were extracted with ethyl acetate (3×50 mL). Thecombined organic layers were washed with water (100 mL), brine (100 mL)and dried over sodium sulfate. The organics were concentrated underreduced pressure to afford N-(5-bromo-4-chloropyridin-2-yl)acetamide asa white solid (14.6 g, 55.9 mmol, quantitative yield) that was usedwithout further purification in the next step. LCMS (ESI) m/e 249[(M+H)⁺, calcd for C₇H₇BrClN₂O 248.9 LC/MS retention time (method B):t_(R)=1.64 min; ¹H NMR (400 MHz, DMSO-d₆) δ 10.87 (s, 1H), 8.58 (s, 1H),8.33 (s, 1H), 2.11 (s, 3H).

Part C. N-(4-chloro-5-vinylpyridin-2-yl)acetamide

To a stirred solution of N-(5-bromo-4-chloropyridin-2-yl)acetamide (7 g,28.1 mmol), 2,4,6-trivinyl-1,3,5,2,4,6-trioxatriborinane complex withpyridine (1:1) (8.78 g, 36.5 mmol), and sodium carbonate (5.95 g, 56.1mmol) solution in 7 mL of water in a mixture of toluene (50 mL) andethanol (8 mL), was added Pd(PPh₃)₄ (0.973 g, 0.842 mmol). The solutionwas purged with nitrogen gas was bubbled for 5 min then heated at 85° C.for 14 h. The reaction was cooled to room temperature and was dilutedwith ethyl acetate (50 mL) ten filtered through a bed of celite. Thefiltrate was diluted with water and the organic layer was separated,washed with brine, dried over sodium sulphate. The organics wereconcentrated under reduced pressure and residue was purified by silicagel column chromatography using a gradient of ethyl acetate in hexanes.Product eluted at 30% ethyl acetate in hexane and required fractionswere concentrated to yield N-(4-chloro-5-vinylpyridin-2-yl)acetamide(5.92 g, 27.7 mmol, 99% yield) as yellow solid. LCMS (ESI) m/e 197.2[(M+H)⁺, calcd for C₉H₁₀ClN₂O 197.04] LC/MS retention time (method A):t_(R)=1.50 min; ¹H NMR (400 MHz, DMSO-d₆) δ 10.79 (s, 1H), 8.64 (s, 1H),8.18 (d, J=6.40 Hz, 1H), 6.88 (dd, J=11.2, 17.6 Hz, 1H), 5.99 (dd,J=17.60, 0.80 Hz, 1H), 5.47 (dd, J=11.40, 0.80 Hz, 1H), 2.12 (s, 3H).

Part D. N-(4-chloro-5-formylpyridin-2-yl)acetamide

To a stirred solution of N-(4-chloro-5-vinylpyridin-2-yl)acetamide (6 g,30.5 mmol) and 2,6-lutidine (7.11 mL, 61.0 mmol) in a mixture of dioxane(110 mL) and water (25 mL) at 0° C. was added osmium tetroxide, 2.5 wt %solution in 2-methyl-2-propanol (9.58 mL, 30.5 mmol) followed by theaddition of sodium periodate (19.58 g, 92 mmol) and the reaction wasstirred for 4 h. The reaction mixture was diluted with water andextracted with ethyl acetate (2×100 mL). The combined organic layerswere washed with brine solution, dried over sodium sulphate,concentrated under reduced pressure. The residue was purified by silicacolumn using hexane/Ethyl acetate to yieldN-(4-chloro-5-formylpyridin-2-yl)acetamide as an off-white solid (5.8 g,28.1 mmol, 92% yield). LCMS (ESI) m/e 197.0 [(M)⁻, calcd forC₈H₆ClN₂O₂197.04] LC/MS retention time (method A): t_(R)=1.21 min; ¹HNMR (400 MHz, DMSO-d₆) δ 11.20 (s, 1H), 10.18 (s, 1H), 8.76 (s, 1H),8.27 (s, 1H), 2.16 (s, 3H).

Part E. N-(4-(4-chloro-2-fluorophenyl)-5-formylpyridin-2-yl)acetamide

To a stirred solution of N-(4-chloro-5-formylpyridin-2-yl)acetamide (3g, 15.11 mmol), (4-chloro-2-fluorophenyl)boronic acid (2.63 g, 15.11mmol), cesium carbonate (9.84 g, 30.2 mmol) in a mixture of water (8 mL)and THF (25 mL) was added Pd(PPh₃)₄ (19.19 mg, 0.017 mmol) and thereaction was heated to 85° C. for 12 h. The reaction mixture was dilutedwith water and extracted with ethyl acetate (2×25 mL). The combinedorganic layers were washed with water, brine, dried over sodiumsulphate, and concentrated under reduced pressure. The residue waspurified by silica gel chromatography using hexane/ethyl acetate aseluant yieldingN-(4-(4-chloro-2-fluorophenyl)-5-formylpyridin-2-yl)acetamide (2.8 g,9.01 mmol, 60% yield) as an off-white solid. LCMS (ESI) m/e 291.0 [(M)⁻,calcd for C₁₄H₉ClFN₂O₂ 291.0] LC/MS retention time (method A):t_(R)=1.69 min; ¹H NMR (400 MHz, DMSO-d₆) δ 11.14 (s, 1H), 9.84 (d,J=Hz, 1H), 8.88 (s, 1H), 8.13 (s, 1H), 7.61 (dd, J=2.00, 10.00 Hz, 1H),7.46-7.48 (m, 2H), 2.11 (s, 3H).

Part F.N-(4-(4-chloro-2-fluorophenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamide

Prepared as described in Example 5, Part C usingN-(4-(4-chloro-2-fluorophenyl)-5-formylpyridin-2-yl)acetamide (9 g,24.29 mmol) to affordN-(4-(4-chloro-2-fluorophenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamide(9 g, quantitative yield) as a brown oil. This was taken to the nextstep without purification. LCMS (ESI) m/e 295.2 [(M)⁻, calcd forC₁₄H₁₃ClFN₂O₂ 295.1] LC/MS retention time (method E): t_(R)=1.44 min.

Part G. N-(8-chloro-5H-chromeno[3,4-d]pyridin-2-yl)acetamide

To a stirred solution ofN-(4-(4-chloro-2-fluorophenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamide(9 g, 23.82 mmol) in DMF (90 mL) was added potassium carbonate (9.88 g,71.5 mmol) and the resultant mixture was sealed tightly and heated at95° C. for 16 h. The reaction mixture was then cooled to roomtemperature and volatiles were removed under reduced pressure. The crudematerial was taken up in water (200 mL) and filtered. The residue waswashed with water (2×250 mL) and dried under reduced pressure for 16 hto afford N-(8-chloro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide (5.5 g,20.02 mmol, 84% yield) as a pale brown solid. LCMS (ESI) m/e 275.2[(m)⁻, calcd for C₁₄H₁₂ClN₂O₂275.1] LC/MS retention time (method D):t_(R)=1.77 min; ¹H NMR (400 MHz, DMSO-d₆) δ 10.6 (s, 1H), 8.41 (s, 1H),8.25 (s, 1H), 7.78 (d, J=8.4 Hz, 1H), 7.22-7.15 (m, 2H), 5.2 (s, 2H),2.2 (s, 3H).

Part H. (S)-tert-butyl1-(2-acetamido-5H-chromeno[3,4-d]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

A stirred suspension ofN-(8-chloro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide (2.5 g, 9.10 mmol),(S)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate (5.93 g, 27.3mmol),di-tert-butyl(2′,4′,6′-triisopropyl-3-methoxy-6-methyl-[1,1′-biphenyl]-2-yl)phosphine(RockPhos) (0.171 g, 0.364 mmol), cesium carbonate (4.45 g, 13.65 mmol)and molecular sieves 4 Å (1.5 g, 9.10 mmol) in toluene (10 mL) werepurged with argon gas for 10 min then treated with allylpalladium(II)chloride (0.067 g, 0.182 mmol). Argon gas was bubbled again for 15 minand the resultant mixture was sealed tightly and heated at 90° C. for 21h. The reaction was cooled to room temperature and diluted with ethylacetate (15 mL) and filtered through celite pad. The filtrate wasevaporated under reduced pressure to afford crude material which waspurified by column chromatography on silica gel (3% methanol inchloroform) to afford the required product contaminated withBoc-leucinol. The oily mixture was then was treated with hexane (2×10mL) to afford white solid which was purified by SFC method (Column:Chiracel OJ-H, (250×4.6)mm, 5μ, 0.5% DEA in acetonitrile) to afford(S)-tert-butyl(1-((2-acetamido-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(2.4 g, 5.24 mmol, 58% yield). ¹H NMR (400 MHz, MeOD) δ 8.31 (s, 1H),8.09 (s, 1H), 7.72 (d, J=8.4 Hz, 1H), 6.71 (dd, J=2.4 Hz, J=8.8 Hz, 1H),6.56 (d, J=2.4 Hz, 1H), 5.09 (s, 2H), 3.95 (m, 3H), 2.20 (s, 3H), 1.72(m, 1H), 1.51-1.39 (m, 2H), 1.47 (s, 9H), 1.16 (m, 6H).

Part I.(S)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Prepared as described in Example 8, Part D using (5)-tert-butyl1-(2-acetamido-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate(4.8 g, 10.54 mmol) to afford(S)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(3.26 g, 9.06 mmol, 86% yield) as a yellow solid. LCMS (ESI) m/e 356.2[(M)⁻, calcd for C₂₀H₂₆N₃O₃356.2] LC/MS retention time (method H):t_(R)=1.55 min; ¹H NMR (400 MHz, MeOD) δ 8.31 (s, 1H), 8.15 (s, 1H),7.83 (d, J=8.4 Hz, 1H), 6.85 (dd, J=2.4 Hz, 8.8 Hz, 1H), 6.71 (d, J=2.8Hz, 1H), 5.15 (s, 2H), 4.31 (dd, J=3.2 Hz, 10.8 Hz, 1H), 4.11 (dd, J=6.4Hz, 10.4 Hz, 1H), 3.72 (m, 1H), 2.25 (s, 3H), 1.65-1.85 (m, 3H), 1.04(m, 6H).

Example 19(S)-4-methyl-1-(spiro[chromeno[3,4-c]pyridine-5,3′-oxetan]-8-yloxy)pentan-2-amine

Part A. 3-(4-chloropyridin-3-yl)oxetan-3-ol

4-Chloropyridine (5 g, 44.0 mmol) hydrochloride salt was dried byazeotropic distillation with anhydrous toluene in a round bottomedflask. To this, anhydrous THF (100 mL) was added under nitrogenatmosphere and cooled to −78° C. After 15 min, LDA, 2M inTHF/heptane/ethylbenzene (48.4 mL, 97 mmol) was added dropwise and thereaction stirred for 30 min. Oxetan-3-one (3.81 g, 52.8 mmol) was thenadded and reaction was stirred for 5 min at −78° C. and then cold bathwas removed and reaction was allowed to warm to room temperaturegradually (−1 h). The reaction was quenched by addition of aqueousammonium chloride and organics extracted with ethyl acetate (3×50 mL).The combined organic extracts were dried and concentrated under reducedpressure to afford 3-(4-chloropyridin-3-yl)oxetan-3-ol (3.8 g, 20.47mmol, 46% yield) as a yellow oil. ¹H NMR (400 MHz, DMSO-d₆) δ 8.6 (s,1H), 8.51 (d, J=5.6 Hz, 1H), 7.56 (d, J=5.2 Hz, 1H), 6.46 (s, 1H), 5.14(m, 2H), 4.73 (m, 2H).

Part B. 3-(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)oxetan-3-ol

Prepared as described in Example 5, Part B using3-(4-chloropyridin-3-yl)oxetan-3-ol to afford3-(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)oxetan-3-ol (750 mg, 2.68mmol, 50% yield) as an off-white solid. LCMS (ESI) m/e 280.0 [(M+H)⁺,calcd for C₁₄H₁₂ClFNO₂ 280.0]; LC/MS retention time (Method E):t_(R)=1.90 min.

Part C. 8-chlorospiro[chromeno[3,4-d]pyridine-5,3′-oxetane]

Prepared as described in Example 5, Part D using3-(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)oxetan-3-ol to afford8-chlorospiro[chromeno[3,4-c]pyridine-5,3′-oxetane] (40 mg, 0.154 mmol,22% yield) as a light brown solid. LCMS (ESI) m/e 260.0 [(M+H)⁺, calcdfor C₁₄H₁₁ClNO₂ 260.0]; LC/MS retention time (Method E): t_(R)=1.92 min.

Part D.(S)-2-(4-methyl-1-(spiro[chromeno[3,4-d]pyridine-5,3′-oxetan]-8-yloxy)pentan-2-yl)isoindoline-1,3-dione

Prepared as described in Example 5, Part E using8-chlorospiro[chromeno[3,4-c]pyridine-5,3′-oxetane] to afford2-(4-methyl-1-(spiro[chromeno[3,4-c]pyridine-5,3′-oxetan]-8-yloxy)pentan-2-yl)isoindoline-1,3-dione(35 mg, 0.074 mmol, 64% yield) as a light brown solid. LCMS (ESI) m/e471.2 [(M+H)⁺, calcd for C₂₈H₂₇N₂O₅ 471.2]; LC/MS retention time (MethodE): t_(R)=2.14 min.

Part E.(S)-4-methyl-1-(spiro[chromeno[3,4-c]pyridine-5,3′-oxetan]-8-yloxy)pentan-2-amine

Prepared as described Example 5, Part F using(S)-2-(4-methyl-1-(spiro[chromeno[3,4-c]pyridine-5,3′-oxetan]-8-yloxy)pentan-2-yl)isoindoline-1,3-dioneto afford(S)-4-methyl-1-(spiro[chromeno[3,4-c]pyridine-5,3′-oxetan]-8-yloxy)pentan-2-amine(13 mg, 0.038 mmol, 51% yield) as a pale brown solid. ¹H NMR (400 MHz,MeOD) δ 8.87 (s, 1H), 8.56 (d, J=5.2 Hz, 1H), 7.85 (d, J=8.4 Hz, 1H),7.76 (d, J=4.8 Hz, 1H), 6.82-6.78 (m, 2H), 5.04 (d, J=8 Hz, 2H), 4.93(d, J=8 Hz, 2H), 4.05 (m, 1H), 3.87 (m, 1H), 3.32 (m, 1H), 1.83 (m, 1H),1.43 (m, 2H), 1.0 (m, 6H); LCMS (ESI) m/e 341.2 [(M+H)⁺, calcd forC₂₀H₂₅N₂O₃ 341.2]; LC/MS retention time (Method E): t_(R)=1.71 min; HPLCretention time (method A): t_(R)=6.93 min; HPLC retention time (methodB): t_(R)=8.53 min.

Example 20(8-(((S)-2-amino-4-methylpentyl)oxy)-5-(chloromethyl)-5H-chromeno[3,4-d]pyridin-5-yl)methanol

To a solution of((S)-tert-butyl(4-methyl-1-(spiro[chromeno[3,4-c]pyridine-5,3′-oxetan]-8-yloxy)pentan-2-yl)carbamate(10 mg, 0.023 mmol) (prepared as described in Example 19, Part D) indichloromethane (1 mL) cooled to 0° C. was added 1M HCl in diethyl ether(23 μL, 0.023 mmol) dropwise and the solution stirred for 30 min. Thereaction was then warmed to room temperature and stirred for 2 h. Aftercompletion of reaction, the volatiles were removed under reduced andpurified by preparative HPLC to afford product(8-(((S)-2-amino-4-methylpentyl)oxy)-5-(chloromethyl)-5H-chromeno[3,4-c]pyridin-5-yl)methanol(2.08 mg, 5.52 μmol, 24% yield) as a yellow solid. ¹H NMR (400 MHz,MeOD) δ 8.82 (m, 1H), 8.69 (m, 1H), 8.35 (m, 1H), 8.09 (m, 1H), 6.94 (m,1H), 6.82 (s, 1H), 4.36-4.20 (m, 6H), 3.73 (m, 1H), 1.82-1.68 (m, 3H),1.04 (m, 6H); LCMS (ESI) m/e 377.2 [(M+H)⁺, calcd for C₂₀H₂₆ClN₂O₃377.2]; LC/MS retention time (Method E): t_(R)=1.71 min; HPLC retentiontime (method A): t_(R)=8.12 min; HPLC retention time (method B):t_(R)=9.87 min.

Example 21(2S)-1-(9-bromo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine

Part A.tert-butyl(2S)-1-(9-bromo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

Prepared as described in Example 14, Part B usingtert-butyl(2S)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-ylcarbamate(prepared as described in Example 6) to affordtert-butyl(2S)-1-(9-bromo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate(120 mg, 0.24 mmol, quantitative) LCMS (ESI) m/e 491.2 [(M+H)⁺, calcdfor C₂₄H₃₂BrN₂O₄ 491.1] LC/MS retention time (method C): t_(R)=2.44 min.

Part B.(2S)-1-(9-bromo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine

Prepared as described in Example 8, Part D usingtert-butyl((2S)-1-((9-bromo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(20 mg, 0.041 mmol) to afford(2S)-1-((9-bromo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine(7 mg, 0.018 mmol, 44% yield) as a yellow solid. ¹H NMR (400 MHz, MeOD)δ 8.69 (bs, 2H), 8.39 (s, 1H), 8.31 (bs, 1H), 6.92 (s, 1H), 5.63 (d,J=5.6 Hz, 1H), 4.42 (m, 1H), 4.28 (m, 1H), 3.77 (bs, 1H), 1.83-1.70 (m,6H), 1.04 (m, 6H). LCMS (ESI) m/e 391.0 [(M+H)⁺, calcd forC₁₉H₂₄BrN₂O₂391.1] LC/MS retention time (method C): t_(R)=1.64 min. HPLCretention time (method A): t_(R)=8.36 min and 8.44 min (Dia mixture);HPLC retention time (method B): t_(R)=5.23 min.

Example 228-((S)-2-amino-4-methylpentyloxy)-5-methyl-5H-chromeno[3,4-c]pyridine-9-carbonitrile

Part A.tert-butyl(2S)-1-(9-cyano-5-methyl-5H-chromeno[3,4-d]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

To a mixture oftert-butyl((2S)-1-((9-bromo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(100 mg, 0.203 mmol) (prepared as described in Example 21, Part A) andL-proline (23.43 mg, 0.203 mmol) in DMF (2 mL) was added copper(I)cyanide (36.5 mg, 0.407 mmol). Argon gas was bubbled through the stirredsuspension for 5 min. The reaction mixture was stirred under argonatmosphere at 120° C. for 12 h. The mixture was then cooled to roomtemperature and diluted with ethyl acetate (10 mL) and filtered throughcelite. The filtrate was washed with water (10 mL) and brine (10 mL).The combined organic extracts were dried over sodium sulfate andconcentrated under reduced pressure to afford crude material which waspurified via silica gel chromatography (pet ether: ethyl acetate mobilephase) to affordtert-butyl((2S)-1-((9-cyano-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(15 mg, 0.034 mmol, 17% yield). LCMS (ESI) m/e 438.2 [(M+H)⁺, calcd forC₂₅H₃₂N₃O₄438.2] LC/MS retention time (method D): t_(R)=1.81 min.

Part B.8-((S)-2-amino-4-methylpentyloxy)-5-methyl-5H-chromeno[3,4-c]pyridine-9-carbonitrile

To a solution oftert-butyl((2S)-1-((9-cyano-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(15 mg, 0.034 mmol) in dichloromethane (2 mL) cooled to 0° C. was addedHCl, 4M in dioxane (1.0 mL, 4.00 mmol) slowly over a period of 1 min.The reaction mixture was stirred at 0° C. for 5 min and then warmed toroom temperature and allowed to stir for 2 h. The solvents were removedunder reduced pressure and the crude material was washed with 5%methanol in ethyl acetate to afford8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridine-9-carbonitrile(9 mg, 0.025 mmol, 73% yield) as a yellow solid. ¹H NMR (400 MHz, MeOD)δ 8.74 (bs, 2H), 8.58 (s, 1H), 8.34 (d, J=6 Hz, 1H), 7.01 (s, 1H), 5.74(t, J=6.4 Hz, 1H), 4.48 (m, 1H), 4.33 (m, 1H), 3.78 (m, 1H), 1.82-1.68(m, 6H), 1.06 (m, 6H). LCMS (ESI) m/e 338.2 [(M+H)⁺, calcd forC₂₀H₂₄N₃O₂ 338.2] LC/MS retention time (method D): t_(R)=1.17 min. HPLCretention time (method A): t_(R)=7.97 min and 8.03 min (diastereomericmixture); HPLC retention time (method B): t_(R)=8.77 min (peaksoverlapped).

Example 23(S)-8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridine-9-carbonitrile

Part A. (S)-tert-butyl1-(9-cyano-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

Prepared as described in Example 22, Part A using (S)-tert-butyl1-(9-bromo-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate(0.029 g, 0.061 mmol) to afford(S)-tert-butyl(1-((9-cyano-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(8 mg, 0.019 mmol, 11% yield) as a light brown solid. LCMS (ESI) m/e424.2 [(M+H)⁺, calcd for C₂₄H₃₀N₃O₄ 424.2] LC/MS retention time (methodE): t_(R)=2.11 min.

Part B.(S)-8-((2-amino-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridine-9-carbonitrile

Prepared as described in Example 8, Part D usingtert-butyl(1-((9-cyano-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(0.008 g, 0.019 mmol) to afford8-((2-amino-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridine-9-carbonitrile(3.19 mg, 9.86 μmol, 52% yield) as a yellow oil. ¹H NMR (400 MHz, MeOD)δ 8.66 (bs, 1H), 8.45 (s, 1H), 8.08 (bs, 1H), 6.95 (s, 1H), 5.43 (s,2H), 4.48 (m, 1H), 4.24 (m, 1H), 3.86 (m, 1H), 3.69 (m, 1H), 1.92-1.74(m, 3H), 1.05 (m, 6H); LCMS (ESI) m/e 324.2 [(M+H)⁺, calcd forC₁₉H₂₂N₃O₂ 324.2]; LC/MS retention time (Method E): t_(R)=1.79 min; HPLCretention time (method A): t_(R)=7.05 min; HPLC retention time (methodB): t_(R)=7.87 min.

Example 24(2S)-1-cyclopentyl-3-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)propan-2-amine

Part A. tert-butyl 1-cyclopentyl-3-hydroxypropan-2-ylcarbamate

To a solution of 2-((tert-butoxycarbonyl)amino)-3-cyclopentylpropanoicacid (730 mg, 2.84 mmol) in THF (7.5 mL) cooled to −10° C. was addedN-methylmorpholine (0.312 mL, 2.84 mmol) followed by isobutylchloroformate (0.373 mL, 2.84 mmol). The reaction mixture was thenstirred for 5 min. The solid obtained was removed by filtration andwashed with THF (5 mL). The filtrate was cooled to −10° C. and treatedwith NaBH₄ (161 mg, 4.26 mmol) in water (5 mL) dropwise. The reactionmixture was stirred at −10° C. for 10 min and allowed to warm to roomtemperature and stirred for another 30 min. The reaction mixture wasthen quenched with cold water (5 mL). The aqueous layer extracted withethyl acetate (3×20 mL). The combined organic layers were washed withbrine (20 mL), dried over sodium sulfate and concentrated under reducedpressure to afford a residue which was purified by column chromatography(pet ether: ethyl acetate) to afford tert-butyl1-cyclopentyl-3-hydroxypropan-2-ylcarbamate (500 mg, 2.05 mmol, 72%yield). ¹H NMR (400 MHz, DMSO-d₆) δ 6.38 (m, 1H), 4.51 (m, 1H),3.85-3.65 (m, 1H), 3.42 (m, 1H), 3.25 (m, 1H), 3.8 (m, 1H), 2.75 (m,1H), 1.85-1.65 (m, 4H), 1.6-1.25 (m, 12H), 1.15 (m, 2H).

Part B.tert-butyl(2S)-1-cyclopentyl-3-(5-methyl-5H-chromeno[3,4-d]pyridin-8-yloxy)propan-2-ylcarbamate

Prepared as described in Example 8, Part C using8-chloro-5-methyl-5H-chromeno[3,4-c]pyridine (100 mg, 0.432 mmol) toafford crude residue which was purified via silica gel chromatography(pet ether and ethyl acetate as a mobile phase) to yieldtert-butyl(1-cyclopentyl-3-((5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)propan-2-yl)carbamate(30 mg, 0.062 mmol, 14% yield) as an off-white solid. LCMS (ESI) m/e439.3 [(M+H)⁺, calcd for C₂₆H₃₅N₂O₄439.3]LC/MS retention time (methodC): t_(R)=2.44 min.

Part C.(2S)-1-cyclopentyl-3-(5-methyl-5H-chromeno[3,4-d]pyridin-8-yloxy)propan-2-amine

Prepared as described in Example 8, Part D usingtert-butyl(1-cyclopentyl-3-((5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)propan-2-yl)carbamate(30 mg, 0.068 mmol) to afford1-cyclopentyl-3-((5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)propan-2-amine(14 mg, 0.040 mmol, 59% yield) as a yellow oil. ¹H NMR (400 MHz, MeOD) δ8.45 (s, 1H), 8.35 (s, 1H), 7.95 (m, 1H), 7.8 (d, J=2.4 Hz, 1H), 6.75(m, 1H), 6.6 (s, 1H), 5.42 (m, 1H), 4.05-4.15 (m, 1H), 3.9-3.85 (m, 1H),3.3-3.1 (m, 1H), 2.0 (m, 1H), 1.95 (m, 2H), 1.9-1.4 (m, 9H), 1.3-1.02(m, 2H); LCMS (ESI) m/e 339.2 [(M+H)⁺, calcd for C₂₁H₂₇N₂O₂ 339.2];LC/MS retention time (Method C): t_(R)=1.53 min; HPLC retention time(Method: Eclipse XDB C18 (4.6×150 mm, 3.5 um), Mobile phase: A=20 mMNH₄OAc in water; Mobile phase B=acetonitrile; 0-12 min, 0% B→10% B;12-15 min, 10% B→100% B; 15-17 min, 100% B; flow rate=1 mL/min; λ=254 nmand 220 nm; run time=17 min): t_(R)=8.22 min; HPLC retention time(method A): t_(R)=9.34 min.

Example 25(S)-8-(2-amino-4-methylpentyloxy)-9-bromo-5H-chromeno[3,4-c]pyridin-5-one

Part A. (S)-tert-butyl1-(9-bromo-5-oxo-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

To a stirred solution of(S)-tert-butyl(4-methyl-1-((5-oxo-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate(0.100 g, 0.242 mmol) (prepared as described in Example 11, Part E) inanhydrous acetonitrile (2 mL) was added NBS (0.043 g, 0.242 mmol) andthe mixture heated to 80° C. for 12 h. After completion of reaction,water (10 mL) was added and extracted with ethyl acetate (2×20 mL). Thecombined organic extracts were dried over sodium sulfate andconcentrated under reduced pressure to afford crude compound which waspurified by preparative TLC to afford(S)-tert-butyl(1-((9-bromo-5-oxo-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(80 mg, 0.163 mmol, 67% yield) as a pale yellow solid. LCMS (ESI) m/e491.2 [(M+H)⁺, calcd for C₂₃H₂₈BrN₂O₅491.1] LC/MS retention time (methodF): t_(R)=1.12 min.

Part B.(S)-8-(2-amino-4-methylpentyloxy)-9-bromo-5H-chromeno[3,4-c]pyridin-5-one

Prepared as described in Example 8, Part D using(5)-tert-butyl(1-((9-bromo-5-oxo-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamateto afford(S)-8-((2-amino-4-methylpentyl)oxy)-9-bromo-5H-chromeno[3,4-c]pyridin-5-one(6 mg, 0.015 mmol, 1% yield) as a white solid. ¹H NMR (400 MHz, MeOD) δ9.38 (s, 1H), 8.89 (d, J=5.6 Hz, 1H), 8.57 (s, 1H), 8.19 (d, J=5.6 Hz,1H), 7.18 (s, 1H), 4.24 (m, 1H), 4.06 (m, 1H), 3.43 (m, 1H), 1.84 (m,1H), 1.63-1.46 (m, 2H), 1.02 (m, 6H). LCMS (ESI) m/e 391.0 [(M+H)⁺,calcd for C₁₈H₂₀BrN₂O₃ 391.1]; LC/MS retention time (Method C):t_(R)=1.53 min; HPLC retention time (method A): t_(R)=11.15 min; HPLCretention time (method B): t_(R)=12.19 min.

Example 264-fluoro-4-methyl-1-(5-methyl-5H-chromeno[3,4-d]pyridin-8-yloxy)pentan-2-amine

Part A. tert-butyl 4-fluoro-1-hydroxy-4-methylpentan-2-ylcarbamate

Prepared as described in Example 24, Part A using2-(tert-butoxycarbonylamino)-4-fluoro-4-methylpentanoic acid (300 mg,1.203 mmol) to afford tert-butyl4-fluoro-1-hydroxy-4-methylpentan-2-ylcarbamate (170 mg, 0.73 mmol, 60%yield) as a pale yellow oil. ¹H NMR (400 MHz, CDCl₃) δ 4.91 (bs, 1H),3.85 (m, 1H), 3.65 (m, 2H), 2.46 (bs, 1H), 1.81 (m, 2H), 1.45 (m, 12H),1.38 (m, 3H).

Part B.tert-butyl-4-fluoro-4-methyl-1-(5-methyl-5H-chromeno[3,4-d]pyridin-8-yloxy)pentan-2-ylcarbamate

Prepared as described in Example 8, Part C usingtert-butyl(4-fluoro-4-methyl-1-((5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate(100 mg, 0.232 mmol) to affordtert-butyl-4-fluoro-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-ylcarbamate(100 mg, 0.204 mmol, 47% yield) as a light brown solid. LCMS (ESI) m/e431.2 [(M+H)⁺, calcd for C₁₉H₂₄FN₂O₂431.2] LC/MS retention time (methodD): t_(R)=1.02 min.

Part C.4-fluoro-4-methyl-1-(5-methyl-5H-chromeno[3,4-d]pyridin-8-yloxy)pentan-2-amine

Prepared as described in Example 8, Part D using8-chloro-5-methyl-5H-chromeno[3,4-c]pyridine (0.100 g, 0.432 mmol) andtert-butyl(4-fluoro-1-hydroxy-4-methylpentan-2-yl)carbamate (0.168 g,0.712 mmol) to afford4-fluoro-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-amine(80 mg, 0.23 mmol, 99% yield) as a yellow oil. ¹H NMR (400 MHz, MeOD) δ8.66 (d, J=6.4 Hz, 1H), 8.64 (s, 1H), 8.24 (d, J=6.4 Hz, 1H), 8.08 (d,J=8.8 Hz, 1H), 6.94 (dd, J=2.4 Hz, 8.8 Hz, 1H), 6.78 (d, J=2.8 Hz, 1H),5.57 (q, J=6.4 Hz, 1H), 4.38 (dd, J=6.4 Hz, J=10.8 Hz, 1H), 4.22 (dd,J=6.4 Hz, 10.8 Hz, 1H), 3.99 (m, 1H), 2.16 (m, 2H), 1.75 (d, J=6.8 Hz,3H), 1.55 (s, 3H), 1.50 (s, 3H); LCMS (ESI) m/e 331.2 [(M+H)⁺, calcd forC₁₉H₂₄FN₂O₂331.2] LC/MS retention time (method D): t_(R)=0.97 min; HPLCretention time (method B): t_(R)=8.04 min.

Example 27(2S)-1-((9-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine

Part A.1-(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)-2,2,2-trifluoroethanol

A stirred solution of 4-(4-chloro-2-fluorophenyl)nicotinaldehyde (1.8 g,7.64 mmol) (prepared as described in Example 5, Part B) and TMS-CF₃(0.521 mL, 3.52 mmol) in dichloromethane (20 mL) was stirred at 0° C.for 20 min. TBAF (1.0 M in THF) (0.4 mL, 1.528 mmol) was added dropwiseslowly and the solution stirred for 90 min. Water was added and thesolution extracted with dichloromethane (2×25 mL). The combined organiclayers were washed with brine, dried over sodium sulphate, concentratedand purified by Prep. TLC using 25% ethyl acetate in hexane to give1-(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)-2,2,2-trifluoroethanol (1 g,2.64 mmol, 35% yield) as a yellow oil. LCMS (ESI) m/e 306.0 [(M+H)⁺,calcd for C₁₃H₉ClF₄NO 306.02]; LC/MS retention time (Method C):t_(R)=2.05 min.

Part B. 8-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridine

Prepared as described in Example 5, Part D using1-(4-(4-chloro-2-fluorophenyl)pyridin-3-yl)-2,2,2-trifluoroethanol toafford 8-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridine (800 mg,2.63 mmol, 80% yield) as a yellow solid. LCMS (ESI) m/e 286.0 [(M+H)⁺,calcd for C₁₃H₈ClF₃NO 286.01]; LC/MS retention time (Method C):t_(R)=2.11 min.

Part C.tert-butyl((2S)-4-methyl-1-((5-(trifluoromethyl)-5H-chromeno[3,4-d]pyridin-8-yl)oxy)pentan-2-yl)carbamate

Prepared as described in Example 8, Part C using(S)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate and8-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridine to affordtert-butyl((2S)-4-methyl-1-((5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate(0.28 g, 0.516 mmol, 49% yield) as a yellow solid. LCMS (ESI) m/e 467.2[(M+H)⁺, calcd for C₂₄H₃₀F₃N₂O₄ 467.2]; LC/MS retention time (Method C):t_(R)=2.19 min.

Part D.tert-butyl((2S)-1-((9-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate

A stirred solution oftert-butyl((2S)-4-methyl-1-((5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate(50 mg, 0.107 mmol) and NCS (14.31 mg, 0.107 mmol) in acetonitrile (12mL) was heated to 60° C. under nitrogen atmosphere for 12 h. The solventwas removed under reduced pressure. The residue was partitioned betweenwater (15 mL) and DCM (15 mL). The organic layer was separated, driedover sodium sulphate and concentrated under reduced pressure to yieldtert-butyl((2S)-1-((9-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(51 mg, 0.092 mmol, 86% yield) as a yellow solid. LCMS (ESI) m/e 501.2[(M+H)⁺, calcd for C₂₄H₂₉ClF₃N₂O₄ 501.2]; LC/MS retention time (MethodD): t_(R)=2.02 min.

Part E.(2S)-1-(9-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-e]pyridin-8-yl)oxy)-4-methylpentan-2-amine

To a stirred solution oftert-butyl((2S)-1-((9-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(50 mg, 0.100 mmol) in DCM (10 mL) was added 1M HCl in diethyl ether(0.100 mmol) at room temperature and the solution stirred for 14 h. Thesolvent was removed under reduced pressure to afford a residue which waspurified by preparative HPLC using 0.1% TFA in methanol. Thepurification afforded(2S)-1-((9-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine(10 mg, 0.023 mmol, 23% yield) as a pale yellow solid. ¹H NMR (400 MHz,DMSO-d₆) δ 8.67 (d, J=5.2 Hz, 1H), 8.57 (s, 1H), 8.32 (s, 1H), 7.98 (d,J=5.2 Hz, 1H), 6.97 (s, 1H), 6.45 (m, 1H), 3.9 (m, 1H), 3.87 (m, 1H),3.09 (m, 1H), 1.83 (m, 1H), 1.33 (m, 2H), 1.31-1.26 (m, 6H); LCMS (ESI)m/e 401.2 [(M+H)⁺, calcd for C₁₉H₂₁ClF₃N₂O₂ 401.1]; LC/MS retention time(Method C): t_(R)=1.69 min; HPLC retention time (method A): t_(R)=5.80min, 5.87 min (diastereomeric mixture); HPLC retention time (method B):t_(R)=6.41 min, 6.45 min (diastereomeric mixture).

Example 27a and 27b(S)-1-((R)-9-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-e]pyridin-8-yl)oxy)-4-methylpentan-2-amineand(S)-1-(((S)-9-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-e]pyridin-8-yl)oxy)-4-methylpentan-2-amine

The diastereomers were resolved with the aid of preparative chiral HPLCusing 0.5% diethyl amine in methanol to afford 2 separate diastereomers(absolute chemistry of CF3 unknown). Obtained diastereomer 1 (36 mg,0.082 mmol, 16% yield) as a yellow gummy liquid. ¹H NMR (400 MHz, CD₃OD)δ 8.62 (d, J=5.2 Hz, 1H), 8.52 (s, 1H), 8.02 (s, 1H), 7.84 (d, J=5.2 Hz,1H), 6.88 (s, 1H), 6.10 (q, J=7.6 Hz, 1H), 4.08 (dd, J=4.4 Hz, J=9.2 Hz,1H) 3.91 (dd, J=6.8 Hz, J=9.2 Hz, 1H), 3.32 (m, 1H), 1.83 (m, 1H), 1.45(m, 2H), 0.99 (m, 6H); LCMS (ESI) m/e 401.2 [(M+H)⁺, calcd forC₁₉H₂₁ClF₃N₂O₂ 401.1]; LC/MS retention time (Method I): t_(R)=1.87 min;HPLC retention time (method A): t_(R)=5.76 min: HPLC retention time(method B): t_(R)=6.28 min. Chiral SFC (0.5% DEA in methanol—ColumnChiralpak AD H (250×4.6)mm-50; t_(R)=1.52 min. Obtained diastereomer 2(38 mg, 0.089 mmol, 17% yield) as a yellow gum: ¹H NMR (400 MHz, CD₃OD)δ 8.61 (d, J=5.2 Hz, 1H), 8.52 (s, 1H), 8.03 (s, 1H), 7.85 (d, J=5.2 Hz,1H), 6.88 (s, 1H), 6.10 (q, J=7.6 Hz, 1H), 4.11 (dd, J=4 Hz, J=9.2 Hz,1H) 3.89 (dd, J=6.8 Hz, J=9.2 Hz, 1H), 3.31 (m, 1H), 1.83 (m, 1H), 1.48(m, 2H), 0.99 (m, 6H); LCMS (ESI) m/e 401.2 [(M+H)⁺, calcd forC₁₉H₂₁ClF₃N₂O₂ 401.1]; LC/MS retention time (Method I): t_(R)=1.86 min;HPLC retention time (method A): t_(R)=5.68 min: HPLC retention time(method B): t_(R)=6.25 min. Chiral SFC (0.5% DEA in methanol—ColumnChiralpak AD H (250×4.6)mm-50; t_(R)=3.93 min.

Example 28(2S)-1-((9-bromo-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine

Part A.tert-butyl((2S)-1-((9-bromo-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate

Prepared as described in Example 14, Part B usingtert-butyl((2S)-4-methyl-1-((5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate(Example 27, Part C) to affordtert-butyl((2S)-1-((9-bromo-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(0.42 g, 0.579 mmol, 75% yield) as a yellow solid. LCMS (ESI) m/e 545.2[(M+H)⁺, calcd for C₂₄H₂₉BrF₃N₂O₄ 545.1]; LC/MS retention time (MethodF) t_(R)=1.1 min.

Part B.(2S)-1-((9-bromo-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine

To a stirred solution oftert-butyl((2S)-1-((9-bromo-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(50 mg, 0.092 mmol) in dichloromethane (10 mL) at room temperature wasadded TFA (0.035 mL, 0.458 mmol) and stirred overnight. The solvent wasremoved under reduced pressure to afford a residue which was purified bypreparative HPLC using 0.1% TFA in MeOH. The purification afforded(2S)-1-((9-bromo-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine(15 mg, 0.033 mmol, 36% yield) as a yellow solid. ¹H NMR (400 MHz, MeOD)δ 8.64 (m, 1H), 8.54 (m, 1H), 8.23 (m, 1H), 7.88 (s, 1H), 6.91 (s, 1H),6.10 (m, 1H), 4.3 (m, 1H), 4.12 (m, 1H), 3.52 (m, 1H), 1.85 (m, 1H),1.72-1.69 (m, 1H), 1.61-1.56 (m, 1H), 1.05 (m, 6H). LCMS (ESI) m/e 445.2[(M+H)⁺, calcd for C₁₉H₂₁BrF₃N₂O₂ 445.1]; LC/MS retention time (MethodC): t_(R)=1.74 min; HPLC retention time (method A): t_(R)=5.66 min, 5.75min (diastereomeric mixture); HPLC retention time (method B): t_(R)=6.27min, 6.34 min (diastereomeric mixture).

Example 298-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-2-amine

Part A.8-chloro-N,N-bis(4-methoxybenzyl)-5-methyl-5H-chromeno[3,4-c]pyridin-2-amine

To a stirred solution ofN-(8-chloro-5-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide (250 mg,0.866 mmol) in DMF (25 mL) was added NaH (62.3 mg, 2.60 mmol) at roomtemperature and stirred for 10 min. 4-Methoxybenzyl chloride (0.236 mL,1.732 mmol) was added dropwise and stirred at room temperatureovernight. The reaction was quenched with ice and extracted with ethylacetate (25 mL). The organic layer was separated, washed with water (25mL), brine (25 mL), dried over sodium sulphate and concentrated underreduced pressure to afford8-chloro-N,N-bis(4-methoxybenzyl)-5-methyl-5H-chromeno[3,4-c]pyridin-2-amine(200 mg, 0.20 mmol, 24% yield) as a yellow oil. This was taken to thenext step without purification. LCMS (ESI) m/e 487.2 [(M±H)⁺, calcd forC₂₉H₂₈ClN₂O₃ 487.2]; LC/MS retention time (Method C): t_(R)=2.52 min.

Part B.tert-butyl(2S)-1-(2-(bis(4-methoxybenzyl)amino)-5-methyl-5H-chromeno[3,4-d]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

Prepared as described in Example 8, Part C using8-chloro-N,N-bis(4-methoxybenzyl)-5-methyl-5H-chromeno[3,4-c]pyridin-2-amineto afford tert-butyl(2S)-1-(2-(bis(4-methoxybenzyl)amino)-5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate(110 mg, 0.070 mmol, 17% yield) as a brown oil. LCMS (ESI) m/e 668.6[(M+H)⁺, calcd for C₄₀H₅₀N₃O₆ 668.4]; LC/MS retention time (Method F):t_(R)=1.49 min.

Part C.8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-2-amine

To a stirred solution oftert-butyl((2S)-1-((2-(bis(4-methoxybenzyl)amino)-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(110 mg, 0.165 mmol) in dichloromethane (10 mL) was added TFA (0.254 mL,3.29 mmol) and the reaction was stirred at room temperature overnight.The volatiles were evaporated and the crude material was purified bypreparative HPLC (0.1% TFA in MeOH) to afford8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-2-amine(25 mg, 0.069 mmol, 42% yield) as a yellow solid. ¹H NMR (400 MHz, MeOD)δ 7.74 (m, 2H), 6.84 (s, 1H), 6.75 (dd, J=2.4 Hz, J=8.4 Hz, 1H), 6.63(d, J=2.4 Hz, 1H), 5.18 (m, 1H), 4.32 (m, 1H), 4.15 (m, 1H), 3.65 (m,1H), 1.83 (m, 1H), 1.65 (m, 5H), 1.04 (m, 6H); LCMS (ESI) m/e 328.2[(M+H)⁺, calcd for C₁₉H₂₆N₃O₂ 328.2]; LC/MS retention time (Method D):t_(R)=1.24 min; HPLC retention time (method A): t_(R)=8.42 min.

Example 30N-(8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Part A.N-(4-(4-chloro-2-fluorophenyl)-5-(1-hydroxyethyl)pyridin-2-yl)acetamide

Prepared as described in Example 6, Part A usingN-(4-(4-chloro-2-fluorophenyl)-5-formylpyridin-2-yl)acetamide (synthesisdescribed in Example 18, Part E) to affordN-(4-(4-chloro-2-fluorophenyl)-5-(1-hydroxyethyl)pyridin-2-yl)acetamide(1.7 g, 4.99 mmol, 91% yield) as a off white solid. LCMS (ESI) m/e 309.2[(M+H)⁺, calcd for C₁₅H₁₅ClFN₂O₂ 309.1]; LC/MS retention time (MethodC): t_(R)=1.54 min.

Part B. N-(8-chloro-5-methyl-5H-chromeno[3,4-d]pyridin-2-yl)acetamide

Prepared as described in Example 18, Part G usingN-(4-(4-chloro-2-fluorophenyl)-5-(1-hydroxyethyl)pyridin-2-yl)acetamideto afford N-(8-chloro-5-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(1.5 g, 3.58 mmol, 65% yield) as a yellow solid. LCMS (ESI) m/e 289.0[(M+H)⁺, calcd for C₁₅H₁₄ClN₂O₂ 289.1]; LC/MS retention time (Method D):t_(R)=1.65 min.

Part C.tert-butyl((2S)-1-((2-acetamido-5-methyl-5H-chromeno[3,4-d]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate

Prepared as described in Example 8, Part C using(S)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate andN-(8-chloro-5-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide to affordtert-butyl((2S)-1-((2-acetamido-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(290 mg, 0.617 mmol, 33% yield) as a yellow oil. LCMS (ESI) m/e 470.3[(M+H)⁺, calcd for C₂₆H₃₆N₃O₅ 470.3]; LC/MS retention time (Method F):t_(R)=0.99 min.

Part D.N-(8-((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-d]pyridin-2-yl)acetamide

Prepared as described in Example 29, Part C usingtert-butyl((2S)-1-((2-acetamido-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamateto affordN-(8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(8 mg, 0.020 mmol, 15% yield) as a yellow solid. ¹H NMR (400 MHz, MeOD)δ 8.35 (s, 1H), 8.12 (s, 1H), 7.78 (d, J=8.8 Hz, 1H), 6.78 (m, 1H), 6.64(d, J=2.4 Hz, 1H), 5.43 (m, 1H), 4.24 (m, 1H), 3.95 (m, 1H), 3.55 (m,1H), 2.22 (s, 3H), 1.81 (m, 1H), 1.55-1.65 (m, 3H), 1.35 (m, 2H), 1.15(m, 6H); LCMS (ESI) m/e 370.2 [(M+H)⁺, calcd for C₂₁H₂₈N₃O₃ 370.2];LC/MS retention time (Method D): t_(R)=1.36 min; HPLC retention time(method A): t_(R)=9.09 min.

Example 31a and 31b(2S)-1-(9-iodo-5-methyl-5H-chromeno[3,4-d]pyridin-8-yloxy)-4-methylpentan-2-amine

Part A.tert-butyl(2S)-1-(9-iodo-5-methyl-5H-chromeno[3,4-d]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

To a solution oftert-butyl((2S)-4-methyl-1-((5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate(200 mg, 0.485 mmol) in acetonitrile (4 mL) was added NIS (654 mg, 2.91mmol) and the mixture refluxed at 80° C. for 12 h. The volatiles wereremoved under reduced pressure. The residue was dissolved in water (10mL) and the aqueous layer was extracted with ethyl acetate (3×10 mL).The combined organic layers were washed with brine (15 mL). The organiclayer was dried over Na₂SO₄ and concentrated under reduced pressure. Thecrude product was purified by silica gel chromatography (pet ether:ethyl acetate) to affordtert-butyl((2S)-1-((9-iodo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(150 mg, 0.237 mmol, 49% yield) as a dark brown oil. LCMS (ESI) m/e539.0 [(M+H)⁺, calcd for C₂₄H₃₂IN₂O₄ 539.1]; LC/MS retention time(method D): t_(R)=1.84 min.

Part B.(2S)-1-(9-iodo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine

Prepared as described in Example 8, Part D usingtert-butyl((2S)-1-((9-iodo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(150 mg, 0.279 mmol) to afford(2S)-1-(9-iodo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine(85 mg, 61% yield) as a yellow oil. LCMS (ESI) m/e 439.0 [(M+H)⁺, calcdfor C₁₉H₂₄IN₂O₂ 439.1]; LC/MS retention time (Method C): t_(R)=1.74 min.The racemate (28 mg, 0.06 mmol) was resolved into diastereomers by prepHPLC purification (TFA in water:MeCN) to afford two diastereomers(absolute stereochemistry of Me unknown). Obtained diastereomer 1 (7 mg,0.015 mmol, 5% yield) as an off-white solid and diastereomer 2 (8 mg,0.017 mmol, 6% yield) as a pale yellow sticky solid.

Diastereomer 1

¹H NMR (400 MHz, MeOD) δ 8.5 (d, J=5.6 Hz, 1H), 8.39 (s, 1H), 8.32 (s,1H), 7.72 (d, J=5.2 Hz, 1H), 6.72 (s, 1H), 5.46 (d, J=6.8 Hz, 1H), 4.28(m, 1H), 4.26 (m, 1H), 4.12 (m, 1H), 1.83 (m, 2H), 1.64 (m, 4H), 1.04(m, 6H); LCMS (ESI) m/e 439.0 [(M+H)⁺, calcd for C₁₉H₂₄IN₂O₂ 439.1]LC/MS retention time (Method E): t_(R)=1.88 min; HPLC retention time(method A): t_(R)=8.56 min; HPLC retention time (method B): t_(R)=10.04min. Method: CHIRAL OD-H (250×4.6) mm 5 micron Mob. phase: 0.2% DEA inn-hexane:ethanol (80:20): t_(R)=8.89 min.

Diastereomer 2

¹H NMR (400 MHz, MeOD) δ 8.6 (d, J=5.2 Hz, 1H), 8.54 (s, 1H), 8.45 (s,1H), 8.01 (d, J=5.6 Hz, 1H), 0.8 (d, J=8.8 Hz, 1H), 5.54 (m, 1H), 4.35(m, 1H), 4.24 (m, 1H), 3.76 (m, 1H), 1.93 (m, 2H), 1.90 (m, 4H), 1.73(m, 6H); LCMS (ESI) m/e 439.0 [(M+H)⁺, calcd for C₁₉H₂₄₁N₂O₂ 439.1]LC/MS retention time (Method E): t_(R)=1.89 min; HPLC retention time(method A): t_(R)=8.63 min; HPLC retention time (method B): t_(R)=10.03min. Method: CHIRAL OD-H (250×4.6) mm 5 micron Mob. phase: 0.2% DEA inn-hexane:ethanol (80:20): t_(R)=15.69 min.

Example 32(S)—N-(8-((2-amino-4-methylpentyl)oxy)-9-chloro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Part A.(S)-tert-butyl(1-((2-acetamido-9-chloro-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate

The stirred solution of(5)-tert-butyl(1-((2-acetamido-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(100 mg, 0.220 mmol) (prepared as described in Example 18, Part H) andNCS (29.3 mg, 0.220 mmol) in acetonitrile (15 mL) was heated to 80° C.for 12 h. The reaction mixture was cooled to room temperature and thesolvent was removed under reduced pressure. The residue was partitionedbetween water (25 mL) and DCM (25 mL). The organic layer was washed withbrine, dried over sodium sulphate and concentrated under reducedpressure to afford(S)-tert-butyl(1-((2-acetamido-9-chloro-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(120 mg, 0.174 mmol, 79% yield) as an off-white solid. The product wasused as is for the next step without purification. LCMS (ESI) m/e 490.2[(M+H)⁺, calcd for C₂₅H₃₃ClN₃O₅ 490.2]; LC/MS retention time (Method D):t_(R)=1.98 min.

Part B.(S)—N-(8-((2-amino-4-methylpentyl)oxy)-9-chloro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Prepared as described in Example 8, Part D using(S)-tert-butyl(1-((2-acetamido-9-chloro-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamateto afford(S)—N-(8-((2-amino-4-methylpentyl)oxy)-9-chloro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(5 mg, 0.012 mmol, 11% yield) as a yellow solid. ¹H NMR (400 MHz, MeOD)δ 8.19 (s, 1H), 8.08 (s, 1H), 7.95 (s, 1H), 6.88 (s, 1H), 5.22 (s, 2H),4.42 (m, 1H), 4.24 (m, 1H), 3.75 (m, 1H), 2.29 (m, 3H), 1.79 (m, 2H),1.72 (m, 1H), 1.18 (m, 6H); LCMS (ESI) m/e 390.2 [(M+H)⁺, calcd forC₂₀H₂₅ClN₃O₃ 390.2]; LC/MS retention time (Method D): t_(R)=1.53 min;HPLC retention time (method A): t_(R)=9.17 min; HPLC retention time(method B): t_(R)=5.14 min.

Example 33(S)-8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-amine

A stirred solution of(S)—N-(8-((2-amino-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(40 mg, 0.113 mmol) and NaOH (45.0 mg, 1.125 mmol) in a mixture ofethanol (10 mL) and water (4 mL) was heated to 90° C. for 18 h. Thevolatiles were removed under reduced pressure and the residue waspartitioned between water (20 mL) and dichloromethane (15 mL). Thelayers were separated and the aqueous layer was extracted withdichloromethane (15 mL). The combined organic layers were dried oversodium sulphate and concentrated under reduced to pressure to affordcrude(S)-8-((2-amino-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-amine(23 mg, 0.068 mmol, 60% crude yield) which was taken in MeOH (2 mL) andcooled to 0° C. The resultant solution was treated with 1M HCl indiethyl ether (15 mL, 0.068 mmol) and the reaction was stirred at roomtemperature for 14 h. The reaction mixture was then cooled to 0° C. toafford a solid which was filtered, washed with diethyl ether (10 mL) anddried under vacuum to afford(S)-8-((2-amino-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-aminedihydrochloride (11 mg, 0.025 mmol, 37% yield for two steps) as a brownsolid. ¹H NMR (400 MHz, MeOD) δ 7.88 (d, J=6.9 Hz, 1H), 7.78 (s, 1H),7.17 (s, 1H), 6.89 (m, 1H), 6.75 (d, J=2.1 Hz, 1H), 5.07 (s, 2H),4.84-4.34 (m, 1H), 4.17-4.13 (m, 1H), 3.71 (m, 1H), 1.82-1.75 (m, 1H),1.73-1.66 (m, 2H), 1.04 (m, 6H). LCMS (ESI) m/e 314.2 [(M+H)⁺, calcd forC₁₈H₂₄N₃O₂ 314.2]; LC/MS retention time (Method D): t_(R)=1.1 min; HPLCretention time (method A): t_(R)=5.16 min; HPLC retention time (methodB): t_(R)=8.96 min.

Example 34(S)-8-((2-amino-4-methylpentyl)oxy)-4-methyl-5H-chromeno[3,4-c]pyridin-5-one

Part A. 2,4-dichloronicotinaldehyde

To a solution of 2,4-dichloropyridine (2 g, 13.51 mmol) intetrahydrofuran (20 mL) at −78° C., was added LDA, 2M inTHF/heptane/ethylbenzene (8.11 mL, 16.22 mmol) and the solution wasstirred for 30 min. DMF (10.46 mL, 135 mmol) was added and the solutionwas stirred for 1 h and then warmed RT. The reaction mixture wasquenched with saturated NH₄Cl solution and diluted with ethyl acetate(50 mL). The organic layer was washed with saturated NaHCO₃ (2×10 mL),water (20 mL), dried over Na₂SO₄ and concentrated under reduced pressureto afford 2,4-dichloronicotinaldehyde (2 g, 11.36 mmol, 84% yield) as ayellow solid. ¹H NMR (400 MHz, CDCl₃) δ 10.49 (s, 1H)), 8.44 (d, J=5.4Hz, 1H), 7.43 (d, J=5.4 Hz, 1H).

Part B. 4-chloro-2-methylnicotinaldehyde

A mixture of 2,4-dichloronicotinaldehyde (1.1 g, 6.25 mmol),2,4,6-trimethyl-1,3,5,2,4,6-trioxatriborinane (0.942 g, 7.50 mmol),Cs₂CO₃ (6.11 g, 18.75 mmol) and PdCl₂(dppf) (0.229 g, 0.312 mmol) in1,4-dioxane (9 mL) and water (1 mL) was heated at 100° C. for 18 h.After cooling, the mixture was diluted with ethyl acetate (15 mL) andwater (20 mL). The ethyl acetate layer was dried over Na₂SO₄,concentrated and purified by silica gel chromatography to afford4-chloro-2-methylnicotinaldehyde (0.16 g, 1.028 mmol, 16% yield) as ayellow solid ¹H NMR (400 MHz, CDCl₃) δ 10.69 (s, 1H), 8.52 (d, J=7.2 Hz,1H), 7.32 (d, J=7.2 Hz, 1H), 2.83 (s, 3H).

Part C. 4-(4-chloro-2-fluorophenyl)-2-methylnicotinaldehyde

A mixture of 4-chloro-2-methylnicotinaldehyde (100 mg, 0.643 mmol),(4-chloro-2-fluorophenyl)boronic acid (123 mg, 0.707 mmol), Cs₂CO₃ (628mg, 1.928 mmol) and Pd(Ph₃P)₄ (52.0 mg, 0.045 mmol) in toluene (5 mL)was heated at 90° C. for 16 h. After cooling, the reaction mixture wasdiluted with EtOAc (10 mL) and water (10 mL). The ethyl acetate layerwas concentrated and purified by silica gel chromatography (2:1Hexane-EtOAc) to afford4-(4-chloro-2-fluorophenyl)-2-methylnicotinaldehyde (0.15 g, 0.601 mmol,35% yield) as a yellow solid. LCMS (ESI) m/e 250.04 [(M+H)⁺, calcd forC₁₃H₁₀ClFNO 250.0]; LC/MS retention time (Method G): t_(R)=0.96 min.

Part D. (4-(4-chloro-2-fluorophenyl)-2-methylpyridin-3-yl)methanol

To a solution of 4-(4-chloro-2-fluorophenyl)-2-methylnicotinaldehyde (60mg, 0.240 mmol) in MeOH (2 mL) at 0° C., was added NaBH₄ (27.3 mg, 0.721mmol) and the solution stirred for 3 h at RT. The mixture wasconcentrated and diluted with EtOAc (15 mL) and water (10 mL). Theorganic layers were dried over Na₂SO₄, filtered and concentrated underreduced pressure to afford(4-(4-chloro-2-fluorophenyl)-2-methylpyridin-3-yl)methanol (0.15 g,0.596 mmol, 89% yield) as a brown solid. LCMS (ESI) m/e 252.03 [(M+H)⁺,calcd for C₁₃H₁₂ClFNO 252.1]; LC/MS retention time (Method G):t_(R)=0.80 min.

Part E. 8-chloro-4-methyl-5H-chromeno[3,4-c]pyridine

To a solution of(4-(4-chloro-2-fluorophenyl)-2-methylpyridin-3-yl)methanol (70 mg, 0.278mmol) in tetrahydrofuran (3 mL) at 0° C. was added NaH (33.4 mg, 0.834mmol) portionwise. The solution was allowed to warm to room temperatureand stirred for 5 h. The reaction mixture was quenched with ice coldwater and diluted with EtOAc (15 mL). The organic layer was dried overNa₂SO₄, filtered and concentrated under reduced pressure to afford8-chloro-4-methyl-5H-chromeno[3,4-c]pyridine (0.11 g, 0.475 mmol, 73%yield) as a brown solid. LCMS (ESI) m/e 232.00 [(M+H)⁺, calcd forC₁₃H₁₂ClNO 232.01]; LC/MS retention time (Method G): t_(R)=1.00 min.

Part F.(S)-tert-butyl(4-methyl-1-((4-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate

A mixture of 8-chloro-4-methyl-5H-chromeno[3,4-c]pyridine (60 mg, 0.259mmol), (S)-(+2-(tert-butoxycarbonylamino)-4-methyl-1-pentanol (113 mg,0.518 mmol), 2-di-t-butylphosphino-2′,4′,6′-tri-1-propyl-1,1′-biphenyl(6.60 mg, 0.016 mmol), Cs₂CO₃ (127 mg, 0.388 mmol) and Pd(OAc)₂ (1.744mg, 7.77 μmol) in toluene (5 mL) was heated at 80° C. for 16 h. Aftercooling to rt, the mixture was diluted with EtOAc (10 mL) and water (10mL). The organic layer was dried over Na₂SO₄, filtered and concentratedunder reduced pressure to afford(S)-tert-butyl(4-methyl-1-((4-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate,(0.2 g, 0.485 mmol, 30% yield) as a yellow solid. LCMS (ESI) m/e 413.39[(M+H)⁺, calcd for C₂₄H₃₃N₂O₄ 413.24]; LC/MS retention time (Method F):t_(R)=0.97 min.

Part G.(S)-8-((2-amino-4-methylpentyl)oxy)-4-methyl-5H-chromeno[3,4-c]pyridin-5-one

A solution of(S)-tert-butyl(4-methyl-1-((4-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate(35 mg, 0.085 mmol) in DCM (3 mL) was cooled to 0° C. and then TFA(0.033 mL, 0.424 mmol) was added. The reaction mixture was stirred atroom temperature for 2 h, then neutralized with saturated NaHCO₃ andextracted with EtOAc (3×5 mL). Organic layer was dried over Na₂SO₄,filtered and concentrated under reduced pressure to afford crude whichwas purified by column chromatography on silica gel to afford materialwhich air oxidized during purification to afford(S)-8-((2-amino-4-methylpentyl)oxy)-4-methyl-5H-chromeno[3,4-c]pyridin-5-one(3 mg, 9.19 umol, 10% yield) as yellow solid. ¹H NMR (400 MHz, CD₃OD) δ8.67 (d, J=5.6 Hz, 1H) 8.19-8.23 (m, 1H) 8.02-8.06 (d, J=5.6 Hz, 1H)7.06-7.10 (m, 1H) 6.98 (s, 1H), 4.08-4.14 (m, 1H), 3.91-3.97 (m, 1H),3.28-3.30 (m, 1H), 3.01 (s, 3H), 1.80-1.88 (m, 1H), 1.41-1.48 (m, 2H),0.97-1.03 (m, 6H); LCMS (ESI) m/e 327.2 [(M+H)⁺, calcd for C₁₉H₂₃N₂O₃327.2]; LC/MS retention time (Method G): t_(R)=0.82 min; HPLC retentiontime (method A): t_(R)=8.47 min; HPLC retention time (method B):t_(R)=8.90 min.

Example 35(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Part A.2-(4-chloro-2-fluoro-3-methylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

To a stirred solution of 1-bromo-4-chloro-2-fluoro-3-methylbenzene (1.70g, 7.61 mmol) in tetrahydrofuran (45 mL) cooled to −10° C. was addedisopropylmagnesium chloride (2.9 M in THF) (3.0 mL, 8.75 mmol) dropwise.The reaction mixture was stirred at −10° C. for 1 h then allowed to warmto 0° C. and stirred for 1 h. The reaction mixture was cooled to −10° C.followed by the addition of2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.785 mL, 8.75mmol) dropwise. The reaction was allowed to warm to room temperature andstirred for 14 h. The reaction mixture was quenched with 1 N aqueoussodium hydroxide solution and stirred for 10 min. The pH of the reactionwas adjusted to 3 with concentrated HCl and the solution was extractedwith ethyl acetate (2×30 mL). The combined organic layers were washedwith water (50 mL), brine (50 mL), dried over sodium sulphate, andconcentrated under reduced pressure to afford2-(4-chloro-2-fluoro-3-methylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane(1.75 g, 6.47 mmol, 85% yield) which was taken to the next step withoutpurification. ¹H NMR (400 MHz, CDCl₃) δ 7.47 (m, 1H), 7.14 (d, J=8 Hz,1H), 2.29 (d, J=2 Hz, 3H), 1.36 (s, 12H).

Part B.N-(4-(4-chloro-2-fluoro-3-methylphenyl)-5-formylpyridin-2-yl)acetamide

Prepared as described in Example 5, Part B using2-(4-chloro-2-fluoro-3-methylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneto affordN-(4-(4-chloro-2-fluoro-3-methylphenyl)-5-formylpyridin-2-yl)acetamide(1.02 g, 3.04 mmol, 82% yield) as a white solid. LCMS (ESI) m/e 307.0[(M+H)⁺, calcd for C₁₅H₁₃ClFN₂O₂ 307.1]; LC/MS retention time (MethodE): t_(R)=1.95 min.

Part C.N-(4-(4-chloro-2-fluoro-3-methylphenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamide

Prepared as described in Example 5, Part C usingN-(4-(4-chloro-2-fluoro-3-methylphenyl)-5-formylpyridin-2-yl)acetamideto affordN-(4-(4-chloro-2-fluoro-3-methylphenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamide(1.1 g, 2.39 mmol, 73% yield) as an off-white solid. LCMS (ESI) m/e309.0 [(M+H)⁺, calcd for C₁₅H₁₅ClFN₂O₂ 309.1]; LC/MS retention time(Method E): t_(R)=1.85 min.

Part D. N-(8-chloro-7-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Prepared as described in Example 5, Part D usingN-(4-(4-chloro-2-fluoro-3-methylphenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamideto afford N-(8-chloro-7-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(150 mg, 0.514 mmol, 18% yield) as a white solid. LCMS (ESI) m/e 289.0[(M+H)⁺, calcd for C₁₅H₁₄ClN₂O₂ 289.1]; LC/MS retention time (Method E):t_(R)=1.9 min.

Part E.(S)-tert-butyl(1-((2-acetamido-7-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate

Prepared as described in Example 8, Part C using(S)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate andN-(8-chloro-7-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide to afford(S)-tert-butyl(1-((2-acetamido-7-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(168 mg, 0.037 mmol, 11% yield) as a brown oil. LCMS (ESI) m/e 470.3[(M+H)⁺, calcd for C₂₆H₃₆N₃O₅ 470.3]; LC/MS retention time (Method F):t_(R)=0.96 min.

Part F.(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Prepared as described in Example 8, Part D using(S)-tert-butyl(1-((2-acetamido-7-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamateto afford yield(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide,TFA salt (9 mg, 0.022 mmol, 64% yield) as a yellow solid. ¹H NMR (400MHz, MeOD) δ 8.18 (s, 1H), 8.11 (s, 1H), 7.76 (d, J=8.4 Hz, 1H), 6.87(d, J=8.8 Hz, 1H), 5.19 (s, 2H), 4.33 (m, 1H), 4.20 (m, 1H), 3.75 (m,1H), 2.27 (s, 3H), 2.23 (s, 3H), 1.8-1.67 (m, 3H), 1.07-1.04 (m, 6H).LCMS (ESI) m/e 370.2 [(M+H)⁺, calcd for C₂₁H₂₈N₃O₃ 370.2]; LC/MSretention time (Method I): t_(R)=1.75 min; HPLC retention time (methodA): t_(R)=9.34 min; HPLC retention time (method B): t_(R)=10.3 min.

Example 36N-(8-((2-amino-5,5,5-trifluoropentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Part A. tert-butyl1-(2-acetamido-5H-chromeno[3,4-c]pyridin-8-yloxy)-5,5,5-trifluoropentan-2-ylcarbamate

Prepared as described in Example 18, Part H usingN-(8-chloro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide (0.1 g, 0.175 mmol)(prepared as described in Example 18, Part G) to affordtert-butyl(1-((2-acetamido-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-5,5,5-trifluoropentan-2-yl)carbamate(0.023 g, 0.021 mmol, 12% yield) as a yellow oil. LCMS (ESI) m/e 496.6[(M+H)⁺, calcd for C₂₄H₂₉F₃N₃O₅ 496.2] LC/MS retention time (method F):t_(R)=0.88 min.

Part B.N-(8-((2-amino-5,5,5-trifluoropentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Prepared as described in Example 8, Part D usingtert-butyl(1-((2-acetamido-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-5,5,5-trifluoropentan-2-yl)carbamate(0.023 g, 0.021 mmol) to affordN-(8-((2-amino-5,5,5-trifluoropentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide,2 TFA (6.02 mg, 9.46 μmol, 44% yield) as a yellow semi solid. ¹H NMR(400 MHz, MeOD) δ 8.18 (s, 1H), 8.01 (s, 1H), 7.87 (d, J=8.8 Hz, 1H),6.89 (m, 1H), 6.76 (d, J=2.8 Hz, 1H), 5.20 (s, 2H), 4.38 (m, 1H), 4.25(m, 1H), 3.82 (m, 1H), 2.52 (m, 2H), 2.32 (s, 3H), 2.15 (m, 2H); LCMS(ESI) m/e 396.2 [(M+H)⁺, calcd for C₁₉H₂₁F₃N₃O₃ 396.1]; LC/MS retentiontime (method H): t_(R)=1.53 min; HPLC retention time (method A):t_(R)=8.13 min; HPLC retention time (method B): t_(R)=8.64 min.

Part A. 3-bromo-6-chloro-2-fluorophenol

To a stirred solution of 1-bromo-4-chloro-2-fluorobenzene (5 g, 23.87mmol) in tetrahydrofuran (40 mL) was cooled to −78° C. was added LDA, 2Min THF/heptane/ethylbenzene (14.92 mL, 29.8 mmol) dropwise and thereaction mixture was stirred at this temperature for 30 min. Thesolution was allowed to warm to −20° C. and stirred for 30 min. Thereaction was cooled to −78° C. and trimethyl borate (3.47 mL, 31.0 mmol)dissolved in THF (5 mL) was added dropwise and the reaction mixture waswarmed to −20° C. and stirred for 1 h. The reaction mixture was cooledto −78° C. and peracetic acid (16 mL, 84 mmol) was added dropwise andthe mixture allowed to warm to rt and stirred for 12 h. The reactionmixture was cooled to 0° C. and quenched with 5% aqueous ammoniumchloride and extracted with ethyl acetate (2×50 mL). The combinedorganic layers were washed with brine (50 mL). The organic layer wasdried over sodium sulphate and concentrated under reduced pressure toyield 3-bromo-6-chloro-2-fluorophenol (4.99 g, 18.25 mmol, 76% yield) asyellow oil. LCMS (ESI) m/e 225.1 [(M+H)⁺, calcd for C₆H₄BrClFO 224.9];LC/MS retention time (method G): t_(R)=0.87 min.

Part B. 1-bromo-4-chloro-2-fluoro-3-methoxybenzene

To a stirred solution of 3-bromo-6-chloro-2-fluorophenol (4.2 g, 18.63mmol) in acetonitrile (35 mL) was added potassium carbonate (5.15 g,37.3 mmol) followed by the addition of methyl iodide (2.330 mL, 37.3mmol) dropwise at rt. The reaction mixture was heated to 85° C. for 3 h.The volatiles were evaporated; water (50 mL) was added and the solutionextracted with ethyl acetate (2×80 mL). The combined organic layers werewashed with brine (100 mL), dried over sodium sulphate, and concentratedunder reduced pressure. The crude material was taken to the next stepwithout further purification. ¹H NMR (400 MHz, CDCl₃) δ 7.20 (m, 1H),7.05 (m, 1H), 3.98 (s, 3H).

Part C.2-(4-chloro-2-fluoro-3-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

To a stirred solution of 1-bromo-4-chloro-2-fluoro-3-methoxybenzene (2.6g, 10.86 mmol) in tetrahydrofuran (30 mL) cooled to −10° C. was addedisopropylmagnesium bromide (4.49 mL, 13.03 mmol) dropwise and thereaction mixture was stirred at this temperature for 1 h. The reactionmixture was then warmed to 0° C. and stirred for 1 h. The reactionmixture was cooled to −10° C. and2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.215 mL, 10.86mmol) was added dropwise. The reaction mixture was warmed to roomtemperature and stirring continued for 16 h. The reaction was quenchedwith 5% aqueous sodium hydroxide and extracted with ethyl acetate (2×25mL). The combined organic layers were washed with brine (25 mL), driedover sodium sulphate, and concentrated under reduced pressure to afford2-(4-chloro-2-fluoro-3-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane(2.15 g, 7.50 mmol, 69% yield) as a brown oil. ¹H NMR (400 MHz, CDCl₃) δ7.35 (m, 1H), 7.13 (m, 1H), 3.96 (s, 3H), 1.36 (s, 12H).

Part D.N-(4-(4-chloro-2-fluoro-3-methoxyphenyl)-5-formylpyridin-2-yl)acetamide

A stirred solution of N-(4-chloro-5-formylpyridin-2-yl)acetamide (1.947g, 8.72 mmol) (prepared as described in Example 18, Part D),2-(4-chloro-2-fluoro-3-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane(2.5 g, 8.72 mmol), cesium carbonate (5.69 g, 17.45 mmol) and Pd(PPh₃)₄(0.504 g, 0.436 mmol) in a mixture of dioxane (30 mL) and water (5 mL)was purged with nitrogen for 5 minutes then heated to 85° C. for 14 h.The reaction mixture was cooled to rt and diluted with water (10 mL).The mixture was extracted with ethyl acetate (2×15 mL). The combinedorganic layers were washed with brine (20 mL), dried over sodiumsulphate, and concentrated under reduced pressure. The residue waspurified by silica gel chromatography using a gradient of ethyl acetatein hexanes to yieldN-(4-(4-chloro-2-fluoro-3-methoxyphenyl)-5-formylpyridin-2-yl)acetamide(1.78 g, 2.95 mmol, 34% yield) as a white solid. LCMS (ESI) m/e 322.9[(M+H)⁺, calcd for C₁₅H₁₃ClFN₂O₃ 323.1]; LC/MS retention time (MethodF): t_(R)=0.89 min.

Part E.N-(4-(4-chloro-2-fluoro-3-methoxyphenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamide

To a stirred solution ofN-(4-(4-chloro-2-fluoro-3-methoxyphenyl)-5-formylpyridin-2-yl)acetamide(1.7 g, 2.370 mmol) in a mixture of THF (15 mL) and methanol (5 mL) wasadded sodium borohydride (0.090 g, 2.370 mmol) in two portions and thereaction mixture was stirred at room temperature for 30 min. Thevolatiles were removed, water (15 mL) was added and the solutionextracted with ethyl acetate (2×20 mL). The combined organic layers werewashed with brine (15 mL), dried over sodium sulphate, and concentratedunder reduced pressure to affordN-(4-(4-chloro-2-fluoro-3-methoxyphenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamide(1.6 g, 1.88 mmol, 38% yield) as a brown solid. The compound was carriedinto the next step without further purification. LCMS (ESI) m/e 324.9[(M+H)⁺, calcd for C₁₅H₁₅ClFN₂O₃ 325.1]; LC/MS retention time (MethodF): t_(R)=0.97 min.

Part F. N-(8-chloro-7-methoxy-5H-chromeno[3,4-d]pyridin-2-yl)acetamide

Prepared as described in Example 5, Part D usingN-(4-(4-chloro-2-fluoro-3-methoxyphenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamideto afford N-(8-chloro-7-methoxy-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(250 mg, 0.743 mmol, 34% yield) as a white solid. LCMS (ESI) m/e 305.0[(M+H)⁺, calcd for C₁₅H₁₄ClN₂O₃ 305.1]; LC/MS retention time (Method G):t_(R)=0.88 min.

Part G.(S)-tert-butyl(1-((2-acetamido-7-methoxy-5H-chromeno[3,4-d]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate

Prepared as described in Example 18, Part H using(5)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate andN-(8-chloro-7-methoxy-5H-chromeno[3,4-c]pyridin-2-yl)acetamide to afford(5)-tert-butyl(1-((2-acetamido-7-methoxy-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(112 mg, 0.089 mmol, 60% yield) as a brown oil. LCMS (ESI) m/e 486.2[(M+H)⁺, calcd for C₂₆H₃₆N₃O₆ 486.2]; LC/MS retention time (Method F):t_(R)=0.91 min.

Part H.(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-methoxy-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

To a stirred solution of(5)-tert-butyl(1-(2-acetamido-7-methoxy-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(111 mg, 0.088 mmol) in dichloromethane (2 mL) was added TFA (0.027 mL,0.352 mmol) dropwise and the reaction mixture was stirred at roomtemperature for 12 h. After completion of reaction, the volatiles wereremoved under reduced pressure to afford a residue which was purified byprep. HPLC (Sunfire C18 3.5 um, 19×150 mm column and 10 mM ammoniumacetate in water) to yield(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-methoxy-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(10 mg, 0.022 mmol, 25% yield) as white solid. ¹H NMR (400 MHz, MeOD) δ8.38 (s, 1H), 8.17 (s, 1H), 7.6 (d, J=8.8 Hz, 1H), 6.88 (d, J=8.8 Hz,1H), 5.18 (s, 2H), 3.9 (s, 3H), 2.2 (s, 3H), 1.94 (m, 3H), 1.86-1.81 (m,1H), 1.70-1.65 (m, 1H), 1.63-1.55 (m, 1H), 1.04 (m, 6H); LCMS (ESI) m/e386.2 [(M+H)⁺, calcd for C₂₁H₂₈N₃O₄ 386.2]; LC/MS retention time (MethodE): t_(R)=1.99 min; HPLC retention time (method A): t_(R)=8.80 min; HPLCretention time (method B): t_(R)=9.73 min.

Example 38(S)—N-(8-(2-amino-4-methylpentyloxy)-7-(difluoromethyl)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Part A,N-(4-(4-chloro-3-(difluoromethyl)-2-fluorophenyl)-5-formylpyridin-2-yl)acetamide

Prepared as described in Example 37, Part D usingN-(4-chloro-5-formylpyridin-2-yl)acetamide (prepared as described inExample 18, Part D), to affordN-(4-(4-chloro-3-(difluoromethyl)-2-fluorophenyl)-5-formylpyridin-2-yl)acetamide(40 mg, 0.1 mmol, 28% yield). LCMS (ESI) m/e 343.0 [(M+H)⁺, calcd forC₁₅H₁₁ClF₃N₂O₂ 343.03]; LC/MS retention time (Method E): t_(R)=1.91 min.

Part B.N-(4-(4-chloro-3-(difluoromethyl)-2-fluorophenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamide

Prepared as described in Example 5, Part C usingN-(4-(4-chloro-3-(difluoromethyl)-2-fluorophenyl)-5-formylpyridin-2-yl)acetamideto affordN-(4-(4-chloro-3-(difluoromethyl)-2-fluorophenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamide(1.1 g, 2.84 mmol, 76% yield) as a brown solid. LCMS (ESI) m/e 345.0[(M+H)⁺, calcd for C₁₅H₁₃ClF₃N₂O₂ 345.0]; LC/MS retention time (Method:H): t_(R)=1.92 min.

Part C.N-(8-chloro-7-(difluoromethyl)-5H-chromeno[3,4-e]pyridin-2-yl)acetamide

Prepared as described in Example 5, Part D using affordN-(4-(4-chloro-3-(difluoromethyl)-2-fluorophenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamideto affordN-(8-chloro-7-(difluoromethyl)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(900 mg, 2.66 mmol, 94% yield) as a pale yellow solid. LCMS (ESI) m/e325.0 [(M+H)⁺, calcd for C₁₅H₁₂ClF₂N₂O₂ 325.0]; LC/MS retention time(Method: H): t_(R)=2.21 min.

Part D. (S)-tert-butyl1-(2-acetamido-7-(difluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

Prepared as described in Example 18, Part H usingN-(8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-4-yl)acetamideto afford(S)-tert-butyl(1-((2-acetamido-7-(difluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(130 mg, 0.152 mmol, 12%) yield as an off white solid. LCMS (ESI) m/e506.2 [(M+H)⁺, calcd for C₂₆H₃₄F₂N₃O₅ 506.2]; LC/MS retention time(Method E): t_(R)=2.09 min.

Part E.(S)—N-(8-(2-amino-4-methylpentyloxy)-7-(difluoromethyl)-5H-chromeno[3,4-d]pyridin-2-yl)acetamide

Prepared as described in Example 8, Part D using(S)-tert-butyl(1-((2-acetamido-7-(difluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(130 mg, 0.152 mmol) to afford(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-(difluoromethyl)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(50 mg, 0.121 mmol, 80% yield) as a white solid. ¹H NMR (400 MHz, MeOD)δ 8.39 (s, 1H), 8.17 (s, 1H), 7.96 (d, J=8.8 Hz, 1H), 7.19 (t, J=54 Hz,1H), 6.91 (d, J=8.8 Hz, 1H), 5.19 (s, 2H), 4.15 (m, 1H), 3.92 (m, 1H),3.27 (m, 1H), 2.22 (s, 3H), 1.81 (m, 1H), 1.44 (m, 2H), 0.99 (m, 6H).LCMS (ESI) m/e 406.2 [(M)⁺, calcd for C₂₁H₂₅F₂N₃O₃ 406.2]; LC/MSretention time (Method J): t_(R)=1.87 min; HPLC retention time (methodA): t_(R)=9.34 min; HPLC retention time (method B): t_(R)=9.95 min.

Example 39(S)-4-methyl-1-((2-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-amine

Part A. Methyl 4-chloro-6-methylnicotinate

A solution of methyl 4,6-dichloronicotinate (2.0 g, 9.71 mmol) in 1,4-dioxane (30 mL) and water (1.5 mL), trimethylboroxine (0.731 g, 5.82mmol), PdCl₂(dppf)-CH₂Cl₂ (0.396 g, 0.485 mmol) and Cs₂CO₃ (9.49 g, 29.1mmol) was degassed with argon for 15 min then heated to 110° C. for 16h. After cooling, the solution was diluted with water (100 mL) andextracted with ethyl acetate (150 mL). The organic layer was dried overNa₂SO₄ and concentrated under reduced pressure. The residue was purifiedby silica gel chromatography (20% EtOAc in pet. ether) to afford methyl4-chloro-6-methylnicotinate (0.1 g, 0.539 mmol, 22% yield) as a yellowoil. LCMS (ESI) m/e 186.0 [(M+H)⁺, calcd for C₈H₉ClNO₂ 186.02]; LC/MSretention time (Method E): t_(R)=1.75 min. ¹H NMR (400 MHz, CDCl₃) δ8.94 (s, 1H), 7.27 (s, 1H), 3.95 (s, 3H), 2.58 (s, 3H).

Part B. Methyl 4-(4-chloro-2-fluorophenyl)-6-methylnicotinate

A mixture of methyl 4-chloro-6-methylnicotinate (0.1 g, 0.539 mmol),(4-chloro-2-fluorophenyl) boronic acid (0.094 g, 0.539 mmol), Pd(PPh₃)₄(0.031 g, 0.027 mmol) and Cs₂CO₃ (0.527 g, 1.616 mmol) in 1,4-dioxane(10 mL) was heated at 80° C. for 16 h. After cooling, the mixture wasdiluted with water (30 mL) and ethyl acetate (50 mL). The organic phasewas collected, dried over Na₂SO₄ and concentrated under reducedpressure. The residue was purified by silica gel chromatography (20%EtOAc in pet. ether) to afford methyl4-(4-chloro-2-fluorophenyl)-6-methylnicotinate (0.045 g, 0.161 mmol, 30%yield) as a yellow liquid. LCMS (ESI) m/e 280.0 [(M+H)⁺, calcd forC₁₄H₁₂ClFNO₂ 280.04]; LC/MS retention time (Method H): t_(R)=2.51 min.¹H NMR (400 MHz, CDCl₃) δ 7.96 (s, 1H), 7.13-7.29 (m, 3H), 6.44 (s, 1H),3.94 (s, 3H), 2.49 (s, 3H).

Part C. (4-(4-chloro-2-fluorophenyl)-6-methylpyridin-3-yl) methanol

To a solution of methyl 4-(4-chloro-2-fluorophenyl)-6-methylnicotinate(0.32 g, 1.144 mmol) in tetrahydrofuran (10 mL) at −10° C., LAH (1.716mL, 1.716 mmol) was added portionwise. The reaction mixture was stirredfor 2 h at RT then diluted with saturated aqueous NH₄Cl (50 mL). Themixture was extracted with ethyl acetate (80 mL). The organic layer wasseparated, dried over Na₂SO₄ and concentrated to afford(4-(4-chloro-2-fluorophenyl)-6-methylpyridin-3-yl) methanol (0.25 g,0.993 mmol, 87% yield) as off-white solid. LCMS (ESI) m/e 252.0 [(M+H)⁺,calcd for C₁₃H₁₂ClFNO 252.0]; LC/MS retention time (Method H):t_(R)=1.60 min; ¹H NMR (400 MHz, CDCl₃) δ 7.69 (s, 1H), 7.52 (s, 1H),7.23 (s, 2H), 7.04-7.17 (m, 1H), 4.57 (d, J=11.60 Hz, 2H), 2.60 (s, 3H).

Part D. 8-chloro-2-methyl-5H-chromeno[3,4-c]pyridine

To a stirred solution of(4-(4-chloro-2-fluorophenyl)-6-methylpyridin-3-yl)methanol (0.25 g,0.993 mmol) in tetrahydrofuran (25 mL) at 0° C. was added NaH (0.06 g,1.49 mmol) portionwise. The solution was then stirred for 16 h at RT.The reaction mixture was quenched with water (100 mL). The precipitatewas collected by filtration and air dried to afford8-chloro-2-methyl-5H-chromeno[3,4-c]pyridine (0.2 g, 0.863 mmol, 69%yield) as a white solid. LCMS (ESI) m/e 232.0 [(M+H)⁺, calcd forC₁₃H₁ClNO 232.0]; LC/MS retention time (Method D): t_(R)=2.06 min; ¹HNMR (400 MHz, CDCl₃) δ 8.31 (s, 1H), 7.65 (d, J=4.40 Hz, 1H), 7.37 (s,1H), 7.07-7.03 (m, 2H), 5.14 (s, 2H), 2.61 (s, 3H).

Part E.(S)-Tert-butyl(4-methyl-1-((2-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate

A mixture of 8-chloro-2-methyl-5H-chromeno[3,4-c]pyridine (0.2 g, 0.863mmol), (S)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate (0.225 g,1.036 mmol), palladium(II) acetate (5.81 mg, 0.026 mmol), Cs₂CO₃ (0.422g, 1.295 mmol) and2-di-tert-butylphosphino-2′,4′,6′-triisopropylbiphenyl (0.022 g, 0.052mmol) in toluene (5 mL) was heated to 110° C. for 18 h. After cooling,the mixture was filtered through celite and concentrated under reducedpressure. The crude product was purified by silica gel chromatography(70% EtOAc in pet. ether) to afford(S)-tert-butyl(4-methyl-1-((2-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate,as a semi-solid (0.12 g, 0.291 mmol, 34% yield). LCMS (ESI) m/e 413.4[(M+H)⁺, calcd for C₂₄H₃₃N₂O₄ 413.2]; LC/MS retention time (Method D):t_(R)=2.42 min.

Part F.(S)-4-methyl-1-((2-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-amine

To a stirred solution of(5)-tert-butyl(4-methyl-1-((2-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate(0.05 g, 0.121 mmol) in MeOH (2 mL) was added 4N HCl in 1,4-dioxane (0.5mL, 16.46 mmol). The reaction mixture was stirred for 4 h at RT. Thereaction mixture was then concentrated and the residue was dissolved inethyl acetate (10 mL). The organic layer was washed with saturatedNaHCO₃ (2×10 mL) and water (20 mL), dried over Na₂SO₄, filtered andconcentrated under reduced pressure to afford a residue which waspurified by prep. HPLC (0.1% ammonium acetate in acetonitrile) to afford(S)-4-methyl-1-((2-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-amine(0.15 g, 0.048 mmol, 32% yield) as a gummy-solid. ¹H NMR (400 MHz,CD₃OD) δ 8.21 (s, 1H); 7.80 (d, J=8.80 Hz, 1H), 7.55 (s, 1H); 6.74 (d,J=10.80 Hz, 1H), 6.60 (d, J=2.40 Hz, 1H), 5.12 (s, 2H), 4.01-3.96 (m,1H), 3.84-3.79 (m, 1H), 3.24-3.22 (m, 1H), 2.53 (s, 3H), 1.82-1.79 (m,1H), 1.42-1.39 (m, 2H), 0.99-0.95 (m, 6H); LCMS (ESI) m/e 312.5 [(M)⁺,calcd for C₁₉H₂₄N₂O₂ 312.2]; LC/MS retention time (Method E): t_(R)=1.63min; HPLC retention time (method A): t_(R)=7.96 min; HPLC retention time(method B): t_(R)=9.01 min.

Example 40(R)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Part A. (R)-tert-butyl1-(2-acetamido-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

Prepared as described in Example 18, Part H using ofN-(8-chloro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide (prepared asdescribed in Example 18, Part G) to afford(R)-tert-butyl(1-((2-acetamido-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(100 mg) as a yellow solid. LCMS (ESI) m/e 456.4 [(M+H)⁺, calcd forC₂₅H₃₄N₃O₅ 456.2]; LC/MS retention time (method E): t_(R)=2.06 min.

Part B.(R)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Prepared as described in Example 8, Part D using(R)-tert-butyl(1-((2-acetamido-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamateto afford(R)—N-(8-((2-amino-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(10.44 mg, 0.029 mmol, 47% yield). ¹H NMR (400 MHz, MeOD) δ 8.25 (s,1H), 8.15 (s, 1H), 7.83 (d, J=8.8 Hz, 1H), 6.84 (m, 1H), 6.72 (d, J=2.8Hz, 1H), 5.16 (s, 2H), 4.34 (m, 1H), 4.15 (m, 1H), 3.75 (m, 1H), 2.26(s, 3H), 1.89-1.65 (m, 3H), 1.15 (m, 6H); LCMS (ESI) m/e 356.2 [(M+H)⁺,calcd for C₂₀H₂₆N₃O₃ 356.2]; LC/MS retention time (method E): t_(R)=1.63min.

Example 41(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-fluoro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Part A. 1-bromo-2,3-difluoro-4-((4-methoxybenzyl)oxy)benzene

To a stirred solution of 4-bromo-2,3-difluorophenol (5 g, 23.92 mmol) inacetonitrile (50 mL) was added potassium carbonate (3.31 g, 23.92 mmol)at room temperature and the reaction mixture was stirred for 5 minfollowed by the addition of 1-(chloromethyl)-4-methoxybenzene (3.75 g,23.92 mmol) dropwise then the reaction mixture was stirred at roomtemperature for 16 h. After the completion of reaction, the volatileswere removed under reduced pressure. Water (100 mL) was added and thesolution extracted with ethyl acetate (2×120 mL). The combined organiclayers were washed with brine (100 mL), dried over sodium sulphate,filtered and concentrated under reduced pressure to afford1-bromo-2,3-difluoro-4-((4-methoxybenzyl)oxy)benzene (7.58 g, 23.03mmol, 96% yield) as a pale brown solid. The product was carried onwithout further purification. LCMS (ESI) m/e 329.1 [(M)⁻, calcd forC₁₄H₁₀BrF₂O₂ 329.0]; LC/MS retention time (Method G): t_(R)=1.20 min.

Part B.2-(2,3-difluoro-4-((4-methoxybenzyl)oxy)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Prepared as described in Example 37, Part C using1-bromo-2,3-difluoro-4-((4-methoxybenzyl)oxy)benzene to afford2-(2,3-difluoro-4-((4-methoxybenzyl)oxy)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane(3.52 g, 9.36 mmol, 77% yield) as a pale yellow solid. ¹H NMR (400 MHz,CDCl₃) δ 7.35 (m, 3H), 6.90 (m, 2H), 6.76 (m, 1H), 5.09 (s, 2H), 3.80(s, 3H), 1.34 (s, 12H).

Part C.N-(4-(2,3-difluoro-4-((4-methoxybenzyl)oxy)phenyl)-5-formylpyridin-2-yl)acetamide

Prepared as described in Example 5, Part B using2-(2,3-difluoro-4-((4-methoxybenzyl)oxy)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneto affordN-(4-(2,3-difluoro-4-((4-methoxybenzyl)oxy)phenyl)-5-formylpyridin-2-yl)acetamide(1.85 g, 4.49 mmol, 48% yield) as a white solid. LCMS (ESI) m/e 413.2[(M+H)⁺, calcd for C₂₂H₁₉F₂N₂O₄ 413.1]; LC/MS retention time (Method E):t_(R)=1.99 min.

Part D.N-(4-(2,3-difluoro-4-((4-methoxybenzyl)oxy)phenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamide

Prepared as described in Example 37, Part E usingN-(4-(2,3-difluoro-4-((4-methoxybenzyl)oxy)phenyl)-5-formylpyridin-2-yl)acetamideto affordN-(4-(2,3-difluoro-4-((4-methoxybenzyl)oxy)phenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamide(2.1 g, 3.29 mmol, 75% yield) as a pale brown solid. LCMS (ESI) m/e415.2 [(M+H)⁺, calcd for C₂₂H₂₁F₂N₂O₄ 415.1]; LC/MS retention time(Method G): t_(R)=0.9 min.

Part E.N-(7-fluoro-8-((4-methoxybenzyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Prepared as described in Example 5, Part D usingN-(4-(2,3-difluoro-4-((4-methoxybenzyl)oxy)phenyl)-5-(hydroxymethyl)pyridin-2-yl)acetamideto affordN-(7-fluoro-8-((4-methoxybenzyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(750 mg, 1.613 mmol, 85% yield) as an off-white solid. LCMS (ESI) m/e395.2 [(M+H)⁺, calcd for C₂₂H₂₀FN₂O₄ 395.1]; LC/MS retention time(Method E): t_(R)=1.95 min.

Part F. (S)-2-((tert-butoxycarbonyl)amino)-4-methylpentylmethanesulfonate

To a stirred solution of(S)-tert-butyl(1-hydroxy-4-methylpentan-2-yl)carbamate (1.6 g, 7.36mmol) in dichloromethane (15 mL) was added triethyl amine (2.052 mL,14.73 mmol) at 0° C. and the solution was stirred for 5 min. To thismixture at 0° C. was added methanesulfonyl chloride (0.574 mL, 7.36mmol) dropwise and the reaction mixture was stirred at room temperaturefor 1 h. The reaction was quenched with water (15 mL) and extracted withDCM (2×15 mL). The combined organic layers were washed with brine (10mL), dried over sodium sulphate, concentrated under reduced pressure toyield (S)-2-((tert-butoxycarbonyl)amino)-4-methylpentyl methanesulfonate(1.7 g, 5.75 mmol, 78% yield) as a yellow solid which was carried onwithout further purification. ¹H NMR (400 MHz, CDCl₃) δ 4.55 (m, 1H),4.25 (m, 1H), 4.16 (m, 1H), 3.92 (m, 1H), 3.05 (s, 3H), 1.66 (m, 2H),1.56 (m, 10H), 0.92 (m, 6H).

Part G. N-(7-fluoro-8-hydroxy-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

To a stirred solution ofN-(7-fluoro-8-((4-methoxybenzyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide(150 mg, 0.380 mmol) in dichloromethane (5 mL) was added TFA (0.059 mL,0.761 mmol) at room temperature and the reaction mixture was stirred atrt for 2 h. After the completion of reaction the volatiles were removedunder reduced pressure. The residue was washed with diethyl ether (7 mL)and stirred for 5 min. The solid was collected by vacuum filtration anddried under vacuum to yieldN-(7-fluoro-8-hydroxy-5H-chromeno[3,4-c]pyridin-2-yl)acetamide, TFA (70mg, 0.170 mmol, 45% yield) as a white solid. LCMS (ESI) m/e 275.0[(M+H)⁺, calcd for C₁₄H₁₂FN₂O₃ 275.1]; LC/MS retention time (Method E):t_(R)=2.0 min.

Part H.(S)-tert-butyl(1-((2-acetamido-7-fluoro-5H-chromeno[3,4-d]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate

To a stirred solution ofN-(7-fluoro-8-hydroxy-5H-chromeno[3,4-c]pyridin-2-yl)acetamide, TFA (70mg, 0.170 mmol) and potassium carbonate (97 mg, 0.704 mmol) in DMF (4mL) was added (S)-2-((tert-butoxycarbonyl)amino)-4-methylpentylmethanesulfonate (52.0 mg, 0.176 mmol) at room temperature and thereaction mixture was heated to 90° C. for 1 h. After completion ofreaction, the volatiles were removed under reduced pressure to afford abrown residue. To this residue water (15 mL) was added and the solutionextracted with ethyl acetate (2×20 mL). The combined organic layers werewashed with water (30 mL), brine (20 mL), dried over sodium sulphate andconcentrated under reduced pressure to afford(S)-tert-butyl(1-((2-acetamido-7-fluoro-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(90 mg, 0.066 mmol, 37% yield) as a brown oil. The product was carriedforward without further purification. LCMS (ESI) m/e 472.2 [(M−H)⁻,calcd for C₂₅H₃₁FN₃O₅ 472.2]; LC/MS retention time (Method E):t_(R)=1.99 min.

Part I.(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-fluoro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Prepared as described in Example 37, Part H using(S)-tert-butyl(1-((2-acetamido-7-fluoro-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamateto afford(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-fluoro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide,0.5 TFA (16 mg, 0.037 mmol, 19% yield) as white solid. ¹H NMR (400 MHz,MeOD) δ 8.42 (s, 1H), 8.19 (s, 1H), 7.65-7.62 (m, 1H), 6.97-6.93 (m,1H), 5.2 (s, 2H), 4.30 (m, 1H), 4.27-4.10 (m, 1H), 3.59-3.51 (m, 1H),2.23 (s, 3H), 1.79 (m, 1H), 1.66-1.56 (m, 2H), 1.21 (m, 6H); LCMS (ESI)m/e 372.2 [(M−H)⁻, calcd for C₂₀H₂₃FN₃O₃ 372.2]; LC/MS retention time(Method E): t_(R)=2.01 min; HPLC retention time (method A): t_(R)=9.04min; HPLC retention time (method B): t_(R)=9.89 min.

Example 42(S)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)cyclopropanecarboxamide

Part A. 8-chloro-5H-chromeno[3,4-c]pyridin-2-amine

N-(8-chloro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide (0.05 g, 0.182mmol) was taken up in 50% aqueous HCl (3 mL, 99 mmol) and refluxed for 3h. The reaction mixture was cooled to room temperature and the volatileswere evaporated under reduced pressure. The residue was treated withwater (3 mL) and extracted with dichloromethane (2×6 mL). The aqueouslayer was collected and concentrated under reduced pressure to afford a8-chloro-5H-chromeno[3,4-c]pyridin-2-amine, hydrochloride (50 mg, 0.185mmol, quantitatively) as a yellow oil. LCMS (ESI) m/e 233.3 [(M+H)⁺,calcd for C₁₂H₁₀ClN₂O 233.0]; LC/MS retention time (method G);t_(R)=0.89 min

Part B.N-(8-chloro-5H-chromeno[3,4-d]pyridin-2-yl)cyclopropanecarboxamide

To a stirred solution of 8-chloro-5H-chromeno[3,4-c]pyridin-2-amine, HCl(0.05 g, 0.186 mmol) in chloroform (2 mL) was added pyridine (0.090 mL,1.115 mmol) followed by addition of cyclopropanecarbonyl chloride (0.034mL, 0.372 mmol) and DMAP (2.270 mg, 0.019 mmol) under nitrogenatmosphere. The reaction mixture was allowed to stir at room temperaturefor 12 h. The mixture was diluted with water (6 mL) then extracted withdichloromethane (2×10 mL). The combined organic layers were dried oversodium sulfate and concentrated under reduced pressure. The residue waspurified by reverse phase HPLC (10 mM ammonium acetate in acetonitrileand water) to affordN-(8-chloro-5H-chromeno[3,4-c]pyridin-2-yl)cyclopropanecarboxamide(0.048 g, 0.156 mmol, 84% yield) as a white solid. LCMS (ESI) m/e 301.0[(M+H)⁺, calcd for C₁₆H₁₄ClN₂O₂ 301.1]; LC/MS retention time (method E):t_(R)=2.53 min.

Part C. (S)-tert-butyl1-(2-(cyclopropanecarboxamido)-5H-chromeno[3,4-d]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate

Prepared as described in Example 18, Part H usingN-(8-chloro-5H-chromeno[3,4-c]pyridin-2-yl)cyclopropanecarboxamide(0.166 g, 0.442 mmol) to afford (S)-tert-butyl1-(2-(cyclopropanecarboxamido)-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-ylcarbamate(200 mg, 0.415 mmol, 55% yield). LCMS (ESI) m/e 482.2 [(M+H)⁺, calcd forC₂₇H₃₆N₃O₅ 482.2]; LC/MS retention time (method F): t_(R)=0.92 min.

Part D.(S)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)cyclopropanecarboxamide

Prepared as described in Example 8, Part D using(S)-tert-butyl(1-((2-(cyclopropanecarboxamido)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate(0.2 g, 0.241 mmol) to afford(S)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)cyclopropanecarboxamide(14 mg, 0.036 mmol, 15% yield) as a white solid. LCMS (ESI) m/e 382.3[(M+H)⁺, calcd for C₂₂H₂₈N₃O₃ 382.2]; LC/MS retention time (Method J):t_(R)=1.96 min; HPLC retention time (method A): t_(R)=10.17 min; HPLCretention time (method B): t_(R)=5.69 min. ¹H NMR (400 MHz, MeOD) δ 8.33(s, 1H), 8.12 (s, 1H), 7.8 (m, 1H), 6.77 (m, 1H), 6.64 (s, 1H), 5.12 (s,2H), 4.12 (m, 1H), 3.96 (m, 1H), 3.44 (m, 1H), 1.93 (m, 1H), 1.90 (m,1H), 1.51 (m, 2H), 1.01 (m, 8H), 0.93 (m, 2H).

Example 43 (S)-methyl8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-ylcarbamate

Part A. methyl 8-chloro-5H-chromeno[3,4-c]pyridin-2-ylcarbamate

Prepared as described in Example 42, Part B using8-chloro-5H-chromeno[3,4-c]pyridin-2-amine (0.1 g, 0.301 mmol) (preparedas in Example 18, Part G) to afford crude which was purified by reversephase HPLC (10 mM ammonium acetate in acetonitrile and water) to affordmethyl (8-chloro-5H-chromeno[3,4-c]pyridin-2-yl)carbamate (0.011 g,0.036 mmol, 12% yield) as a white solid. LCMS (ESI) m/e 291.0 [(M+H)⁺,calcd for C₁₄H₁₂ClN₂O₃ 291] LC/MS retention time (method E): t_(R)=1.96min; ¹H NMR (400 MHz, DMSO-d₆) δ 10.3 (s, 1H), 8.23 (s, 1H), 8.22 (s,1H), 7.83 (d, J=8.8 Hz, 1H), 7.21 (m, 1H), 7.17 (s, 1H), 5.20 (s, 2H),3.72 (s, 3H).

Part B.methyl(S)-(8-((2-((tert-butoxycarbonyl)amino)-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)carbamate

Prepared as described in Example 18, Part H using methyl(8-chloro-5H-chromeno[3,4-c]pyridin-2-yl)carbamate (0.16 g, 0.176 mmol)to afford crude material which was purified by using silica gelchromatography (2.5% methanol in chloroform) to afford methyl(5)-(8-((2-((tert-butoxycarbonyl)amino)-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)carbamate(0.15 g, 0.067 mmol, 38% yield) as a yellow oil. LCMS (ESI) m/e 472.2[(M+H)⁺, calcd for C₂₅H₃₄N₃O₆472.2]; LC/MS retention time (method F):t_(R)=0.95 min.

Part C. (S)-methyl8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-ylcarbamate

Prepared as described in Example 8, Part D using(S)-(8-((2-((tert-butoxycarbonyl)amino)-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)carbamate(0.15 g, 0.067 mmol) to afford crude material which was purified byreverse phase HPLC (10 mM ammonium acetate in acetonitrile and water) toafford (S)-methyl(8-((2-amino-4-methylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)carbamate(5 mg, 0.013 mmol, 19% yield) as a white solid. ¹H NMR (400 MHz, MeOD) δ8.14 (s, 1H), 8.06 (d, J=0.8 Hz, 1H), 7.78 (d, J=8.8 Hz, 1H), 6.77 (m,1H), 6.62 (d, J=2.4 Hz, 1H), 5.11 (s, 2H), 4.04 (m, 1H), 3.86 (m, 1H),3.82 (s, 3H), 3.32 (m, 1H), 1.86 (m, 1H), 1.42 (m, 2H), 0.99 (m, 6H);LCMS (ESI) m/e 372.2 [(M+H)⁺, calcd for C₂₀H₂₆N₃O₄372.2]; LC/MSretention time (method E): t_(R)=2.13 min; HPLC retention time (methodA): t_(R)=9.39 min; HPLC retention time (method B): t_(R)=10.15 min.

Example 44N-(8-(2-amino-2,4-dimethylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Part A. 2-(tert-butoxycarbonylamino)-2,4-dimethylpentanoic acid

To a stirred solution of 2-amino-2,4-dimethylpentanoic acid (1 g, 6.89mmol) in tetrahydrofuran (15 mL) and water (15 mL) was added K₂CO₃ (3.81g, 27.5 mmol) and the reaction mixture was stirred at room temperaturefor 10 min. To the resultant mixture (BOC)₂O (3.20 mL, 13.77 mmol) wasadded dropwise and the reaction mixture was allowed to stir at roomtemperature for 14 h. The reaction mixture was then concentrated underreduced pressure. The aqueous layer was washed with ethyl acetate (3×15mL) and acidified with a saturated aqueous solution of citric acid (25mL) then extracted with ethyl acetate (3×50 mL). The combined organicextracts were washed with water (2×15 mL), brine (20 mL), dried oversodium sulfate and concentrated under reduced pressure to afford2-((tert-butoxycarbonyl)amino)-2,4-dimethylpentanoic acid (1.6 g, 6.89mmol, quantitative yield) as a white solid. ¹H NMR (400 MHz, CDCl₃) δ5.36 (bs, 1H), 2.10 (m, 1H), 1.77 (m, 2H), 1.74-1.65 (m, 3H), 1.59 (s,9H), 0.89 (m, 3H), 0.94 (m, 3H).

Part B. tert-butyl 1-hydroxy-2,4-dimethylpentan-2-ylcarbamate

To a stirred solution of2-((tert-butoxycarbonyl)amino)-2,4-dimethylpentanoic acid (1.6 g, 6.52mmol) in tetrahydrofuran (40 mL) cooled to −10° C. under nitrogenatmosphere was added N-methylmorpholine (0.860 mL, 7.83 mmol) followedby isobutyl chloroformate (1.028 mL, 7.83 mmol) dropwise and thereaction mixture was stirred for 30 min. The reaction mixture was thenfiltered and the filtrate was added dropwise to a suspension of NaBH₄(0.494 g, 13.04 mmol) in water (20.0 mL). The reaction mixture wasstirred for 10 min then diluted with ethyl acetate (30 mL). The organiclayer was separated and washed with brine (2×20 mL), dried over (Na₂SO₄)and evaporated under reduced pressure. The residue was purified bysilica gel chromatography (30% ethyl acetate and pet ether) to affordtert-butyl(1-hydroxy-2,4-dimethylpentan-2-yl)carbamate (1.1 g, 4.76mmol, 73% yield) as an oil. ¹H NMR (400 MHz, DMSO-d₆) δ 6.09 (s, 1H),4.61 (t, J=7.6 Hz, 1H), 3.35 (m, 2H), 1.8-1.6 (m, 2H), 1.44-1.35 (m,10H), 1.09 (s, 3H), 0.86 (m, 6H).

Part C. tert-butyl1-(2-acetamido-5H-chromeno[3,4-d]pyridin-8-yloxy)-2,4-dimethylpentan-2-ylcarbamate

Prepared as described in Example 18, Part H usingN-(8-chloro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide (0.3 g, 1.092 mmol)(prepared as in Example 18, Part G) to afford crude material which waspurified by reverse phase HPLC (10 mM ammonium acetate) to affordracemictert-butyl(1-((2-acetamido-5H-chromeno[3,4-e]pyridin-8-yl)oxy)-2,4-dimethylpentan-2-yl)carbamate(60 mg, 0.116 mmol, 12% yield) as a yellow semi solid. ¹H NMR (400 MHz,MeOD) δ 9.33 (s, 1H), 8.11 (s, 1H), 7.74 (d, J=8.8 Hz, 1H), 6.74 (m,1H), 6.58 (d, J=2.4 Hz, 1H), 5.11 (s, 2H), 4.18 (d, J=9.2 Hz, 1H), 3.97(d, J=9.2 Hz, 1H), 2.21 (s, 3H), 1.87 (m, 2H), 1.62 (m, 1H), 1.42 (s,9H), 1.36 (s, 3H), 0.99 (m, 6H); LCMS (ESI) m/e 470 [(M+H)⁺, calcd forC₂₆H₃₆N₃O₅ 470.25]; LC/MS retention time (Method K): t_(R)=2.48 min.

Part D.N-(8-(2-amino-2,4-dimethylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide

Prepared as described in Example 8, Part D usingtert-butyl(1-((2-acetamido-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-2,4-dimethylpentan-2-yl)carbamate(0.55 g, 0.433 mmol) to afford crude material which was purified byreverse phase HPLC (10 mM ammonium acetate in acetonitrile and water) toaffordN-(8-(2-amino-2,4-dimethylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide.To make the HCl salt, the compound was dissolved in methanol (1 mL),cooled to 0° C. and treated with 4M HCl in dioxane (1.5 mL) and stirredfor 10 min. The volatiles were concentrated under reduced pressure andthe solution was lyophilized to afford racemicN-(8-((2-amino-2,4-dimethylpentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide,HCl (0.013 g, 0.030 mmol, 7% yield) as a pale yellow solid. ¹H NMR (400MHz, MeOD) δ 8.21 (s, 1H), 7.94 (d, J=8.8 Hz, 1H), 7.86 (bs, 1H), 6.94(m, 1H), 6.79 (s, 1H), 5.25 (s, 2H), 4.29 (d, J=10.4 Hz, 1H), 4.16 (d,J=10.4 Hz, 1H), 2.33 (s, 3H), 1.88 (m, 2H), 1.72 (m, 1H), 1.52 (s, 3H),1.06 (m, 6H); LCMS (ESI) m/e 370.4 [(M+H)⁺, calcd for C₂₁H₂₈N₃O₃ 370.2];LC/MS retention time (Method J); HPLC retention time (method A):t_(R)=9.51 min; HPLC retention time (method B): t_(R)=9.98 min.

Methods AAK1 Kinase Assay

The assays were performed in U-bottom 384-well plates. The final assayvolume was 30 μl prepared from 15 μl additions of enzyme and substrates(fluoresceinated peptide (5-FAM)-Aha-KEEQSQITSQVTGQIGWR-NH2 and ATP) andtest compounds in assay buffer (10 mM Tris-HCL pH 7.4, 10 mM MgCl₂,0.01% Tween-20 and 1.0 mM DTT). The reactions were initiated by thecombination of bacterially expressed, GST-Xa-hAAK1 with substrates andtest compounds. The reactions were incubated at room temperature for 3hours and terminated by adding 60 μl of 35 mM EDTA buffer to eachsample. The reactions were analyzed on the Caliper LabChip 3000(Caliper, Hopkinton, Mass.) by electrophoretic separation of thefluorescent substrate and phosphorylated product. Inhibition data werecalculated by comparison to EDTA quenched control reactions for 100%inhibition and vehicle-only reactions for 0% inhibition. The finalconcentration of reagents in the assays are ATP, 22 μM;(5-FAM)-Aha-KEEQSQITSQVTGQIGWR-NH2, 1.5 μM; GST-Xa-hAAK1, 3.5 nM; andDMSO, 1.6%. Dose response curves were generated to determine theconcentration required inhibiting 50% of kinase activity (IC₅₀).Compounds were dissolved at 10 mM in dimethylsulfoxide (DMSO) andevaluated at eleven concentrations. IC₅₀ values were derived bynon-linear regression analysis.

HEK281 Cell-Based Assay

HEK293F cells were cultured in media containing DMEM (Gibco, cat.#11965), 10% FBS (SAFC Biosciences, cat. #12103C), 1× GPS (glutamine,penicillin and streptomycin). On day one, cells were plated on a 10 cmdish so that they are ˜80% confluent at time of transfection. Roughly 12million cells were in a 10 cm dish at time of transfection. On day two,each dish was transfected with 48 ug DNA and 144 ul Lipofectamine 2000(Invitrogen, cat. #11668-019). The DNA was comprised of a mixture (per10 cm dish) containing 3 ug AAK1/HA/pIRES (full length human, NCBIaccession no. NP_(—)055726.2), 45 μg Flag/AP2MI/pcDNA (full lengthhuman), and 1.5 ml OPTI-MEM. The Lipofectamine 2000 is made up of amixture (per 10 cm dish) containing 144 μl Lipofectamine 2000 and 1.5 mlOPTI-MEM. Each mixture was transferred to individual 15 ml tubes andincubated at RT for 5 minutes, and then the two mixes were combined andincubated at RT for 20 minutes. Growth media was then aspirated fromeach 10 cm plate and replaced with 10 ml of DMEM+10% FBS (no GPS).Finally, 3 ml DNA/Lipofectamine mix was added to each 10 cm dish and mixgently followed by incubate of plate overnight at 37° C. and 5% CO₂.

On day three, compounds were diluted in 100% DMSO at 1000× finalconcentration, followed by 3-fold serial dilutions for a total of 5concentrations tested. Four compounds were tested per 10 cm dish. One ulof each compound dilution was then pipetted into a deep-well, 96-wellplate, followed by addition of 500 μl DMEM+0.5% FBS into each well for a2× final concentration of each compound. Cells were resuspended in a 10cm dish by simple pipetting (HEK293 cells come off the plate that easyat this point) and then transferred to a 50 ml conical tube and pelletedby centrifugation at 1000 rpm for 5 min. Cell pellets were thenresuspended in 2.75 ml DMEM+0.5% FBS per 10 cm dish and 100 μl of cellsuspension transferred into each well of 96-well TC plate. Finally, 100μl of 2× compound diluted in DMEM+0.5% FBS was then added into wellscontaining cell suspension for a 1× final concentration. Plates werethen incubated at 37° C. and 5% CO₂ for 3 hours followed by transferringof cell suspensions from each well into 12-tube PCR strips. The PCRstrips were spun in a tip rack at 1000 rpm for 5 minutes to pellet cellsand media was then removed by pipetting without disturbing the cellpellet.

To prepare for Western Blot analysis, cell pellets were resuspend in 40ul 1× LDS-PAGE sample buffer (Invitrogen, cat. #NP0008)+2× Haltphophatase and protease inhibitor cocktail (Thermo Scientific, cat.#1861284), followed by sonicating each with microtip sonicator set at 5for 8-10 seconds. Five ul of 10× NuPage Sample Reducing Agent (with 50mM DTT) was to each sample followed by heat denaturing at 70C for 10 minon PCR machine. A total of 10 μl per sample was loaded into each lane ofa 4-20% Tris-Glycine Criterion 26-well gel (Biorad, cat. #345-0034) forthe phospho-mu2 blot and 10 μl per lane in a 4-12% Bis-Tris (+MESbuffer) NuPAGE 26-well gel (Invitrogen, cat. #WG1403BX10) for the mu2blot. For controls, 2 ng of phospho-mu2 or 20 ng mu2/Flag proteins wereloaded in the last well of each gel. After SDS-PAGE, samples on each gelwere transferred to PVDF membrane using an iBlot and membranes wereblocked for one hour in TBST+5% milk, followed by wash 3× for 5-10 minwith TBST. Criterion gels were probed with rabbit anti-phospho-mu2(1:5000; a rabbit polyclonal antibody produced by New England Peptideand affinity purified at Lexicon) in TBST+5% BSA, whereas, NuPAGE gelswere probed with mouse anti-Flag (1:500; Sigma, cat. #F1804) in TBST+5%milk, and these primary antibodies were incubated overnight at 4° C. ona rocker.

On day four, Western blots were washed 3× for 5-10 minutes with TBST,probe with anti-rabbit-HRP (1:2000; BioRad, cat. #170-6515) oranti-mouse-HRP (1:2000; Biorad, cat. #170-6516) in TBST+5% milk for 1hour at RT, washed 3× for 10 minutes with TBST, and developed with ECLreagent (GE Healthcare, cat. #RPN2132) on a Versadoc. Finally, thecamera was set up to take a picture every 30 seconds for 10 minutes andthe best image saved for each blot with no saturated signal (when thesignal is saturated, the bands will be highlighted red). A volumeanalysis on each band was performed to obtain density values. Percentinhibition was calculated for each sample by first normalizing to totalMu2 expression levels and then comparing to 0% and 100% controls. IC₅₀values were then calculated using Excel fitting software.

AAK1 Knockout Mice

Mice homozygous (−/−) for the disruption of the AAK1 gene were preparedby two methods; gene trapping and homologous recombination. Genetrapping is a method of random insertional mutagenesis that uses afragment of DNA coding for a reporter or selectable marker gene as amutagen. Gene trap vectors have been designed to integrate into intronsor genes in a manner that allows the cellular splicing machinery tosplice vector encoded exons to cellular mRNAs. Commonly, gene trapvectors contain selectable marker sequences that are preceded by strongsplice acceptor sequences and are not preceded by a promoter. Thus, whensuch vectors integrate into a gene, the cellular splicing machinerysplices exons from the trapped gene onto the 5′ end of the selectablemarker sequence. Typically, such selectable marker genes can only beexpressed if the vector encoding the gene has integrated into an intron.The resulting gene trap events are subsequently identified by selectingfor cells that can survive selective culture.

Embryonic stem cells (Lex-1 cells from derived murine strain A129), weremutated by a process involving the insertion of at least a portion of agenetically engineered vector sequence into the gene of interest, themutated embryonic stem cells were microinjected into blastocysts whichwere subsequently introduced into pseudopregnant female hosts andcarried to term using established methods. See, e.g., “MouseMutagenesis”, 1998, Zambrowicz et al., eds., Lexicon Press, TheWoodlands, Tex. The resulting chimeric animals were subsequently bred toproduce offspring capable of germline transmission of an allelecontaining the engineered mutation in the gene of interest.

AAK1-gene disrupted mice were also made by homologous recombination. Inthis case, the second coding exon of the murine AAK1 gene (see GenBankAccession Number NM_(—)177762) was removed by methods known in the art.See, e.g., U.S. Pat. Nos. 5,487,992, 5,627,059, and 5,789,215.

Mice homozygous (−/−) for the disruption of the AAK1 gene were studiedin conjunction with mice heterozygous (+/−) for the disruption of theAAK1 gene, and wild-type (+/+) litter mates. During this analysis, themice were subject to a medical work-up using an integrated suite ofmedical diagnostic procedures designed to assess the function of themajor organ systems in a mammalian subject. Homozygous (−/−) “knockout”mice were studied in conjunction with their heterozygous (+/−) andwild-type (+/+) litter mates. Disruption of the AAK1 gene was confirmedby Southern analysis. Expression of the murine homolog of AAK1 wasdetected by RT-PCR in murine brain; spinal cord; eye; thymus; spleen;lung; kidney; liver; skeletal muscle; bone; stomach, small intestine andcolon; heart; adipose; asthmatic lung; LPS liver; blood; banded heart;aortic tree; prostate; and mammary gland (5 week virgin, mature virgin,12 DPC, 3 day post-partum (lactating), 3 day post-weaning (earlyinvolution), and 7 day post-weaning (late involution)).

AAK1 homozygous (−/−) and their wild-type (+/+) littermates were testedusing the formalin paw test in order to assess their acute and tonicnociceptive responses. For these tests, Automatic Nociception Analyzers(purchased from the Ozaki lab at University of California, San Diego)were used. A metal band was placed around the left hind paw of eachmouse 30 minutes prior to testing. After the 30-minute acclimationperiod, 20 μl of 5% formalin is subcutaneously injected in the dorsalsurface of the left hind paw. Mice were individually housed incylindrical chambers for 45 minutes. Fresh 5% formalin solution wasprepared by diluting formaldehyde (Formalde-fresh 20%, FisherScientific, Fair Lawn, N.J.) with distilled water. Investigatorycompounds were administered 30 minutes prior to formalin injection.

A computer recorded flinches per minute, total flinches for phase I(acute phase=first 8 minutes), and total flinches for phase II (tonicphase=time between minutes 20-40) through an electromagnetic field. SeeYaksh T L, Ozaki G, McCumber D, Rathbun M, Svensson C, Malkmus S, YakshM C. An automated flinch detecting system for use in the formalinnociceptive bioassay. J Appl Physiol., 2001; 90:2386-402.

As shown in FIG. 1, phase 1 and phase 2 data were obtained usinghomozygous (−/−) mice females (n=16), wild-type females (n=15),homozygous (−/−) mice males (n=9), and wild-type males (n=18). In allgroups and in both phases, the AAK1 homozygous (−/−) mice exhibitedsignificantly less recorded paw flinching than their wild-type (+/+)littermates.

Studies of AAK1 knockout mice showed that disruption of the AAK1 geneaffects pain response as measured using the formalin paw test describedabove. The same test was used to confirm that the administration of anAAK1 inhibitor can also affect pain response.

A compound of the disclosure was tested in this assay at differentdoses. Gabapentin and pregabalin were used as positive controls. Resultsare shown below in Table 2, wherein the effect of gabapentin at 200mg/kg is considered a 100% response, the % response for the othercompounds is relative to the 200 mg/kg dose of gabapentin, “sc” meanssubcutaneous administration.

TABLE 2 Dose Compound (mg/kg) Response Gabapentin 50 sc 60% Gabapentin200 sc  100%  Pregabalin 50 sc 90% Compound 5:(R)-1-(5H-chromeno[3,4-c]pyridin-8- 10 sc 45%yloxy)-4-methylpentan-2-amine Compound 5:(R)-1-(5H-chromeno[3,4-c]pyridin-8- 30 sc 88%yloxy)-4-methylpentan-2-amine

What is claimed is:
 1. A compound of formula (I)

or a pharmaceutically acceptable salt thereof, wherein: R¹ and R² areindependently selected from hydrogen, C₃-C₆cycloalkyl, and C₁-C₃alkylwherein the C₁-C₃alkyl is optionally substituted with one, two, or threegroups independently selected from C₁-C₃alkoxy, C₁-C₃alkylamino, amino,cyano, C₁-C₃dialkylamino, halo, and hydroxy; or R¹ and R² together areoxo; or R¹ and R², together with the carbon atom to which they areattached, form an oxetane ring; R³ is C₁-C₃alkyl-Y or C₂-C₈alkyl,wherein the C₂-C₈alkyl is optionally substituted with one, two, three,or four groups independently selected from C₁-C₃alkoxy, C₁-C₃alkylamino,C₁-C₃alkoxyC₂-C₃alkylamino, amino, aryl, halo, C₁-C₃haloalkylamino,C₁-C₃haloalkylcarbonylamino, hydroxy, —NR^(x)R^(y), and C₃-C₈cycloalkyl,wherein the cycloalkyl is further optionally substituted with one, two,or three groups independently selected from C₁-C₃alkoxy, C₁-C₃alkyl,C₁-C₃alkylamino, C₁-C₃alkoxyC₂-C₃alkylamino, amino, aryl,arylC₁-C₃alkyl, halo, C₁-C₃haloalkyl, C₁-C₃haloalkylamino and hydroxy;R⁴ is selected from hydrogen, C₁-C₃alkoxy, C₁-C₃alkoxycarbonylamino,C₁-C₃alkyl, C₁-C₃alkylamino, C₁-C₃alkylcarbonylamino, amino, arylamino,arylcarbonylamino, C₃-C₆cycloalkylamino, C₃-C₆cycloalkylcarbonylamino,C₃-C₆cycloalkyloxy, halo, C₁-C₃haloalkoxy, C₂-C₃haloalkylamino,C₂-C₃haloalkylcarbonylamino, and hydroxy; R⁵ is selected from hydrogen,C₁-C₃alkyl, cyano, C₃cycloalkyl, and halo; R⁶ is selected from hydrogen,C₁-C₃alkyl, C₁-C₃alkylcarbonylamino, amino, R⁷ is selected fromhydrogen, C₁-C₃alkoxy, C₁-C₃alkyl, cyano, —CH₂OH, —CH₂OCH₃, CH(CH₃)OH,C(CH₃)₂OH, halo, and C₁-C₃haloalkyl; R⁸ is selected from hydrogen,C₁-C₃alkoxy, cyano, and halo; R^(x) and R^(y), together with thenitrogen atom to which they are attached, form a three- to six-memberedring; and Y is selected from

wherein R⁹ is selected from hydrogen, C₁-C₆alkyl, C₃-C₆cycloalkyl, andC₁-C₆alkylcarbonyl; n is 0, 1, 2, or 3; each R¹⁰ is independentlyselected from hydrogen, C₁-C₆alkyl, aryl, arylC₁-C₃alkyl,C₃-C₆cycloalkyl, halo, and C₁-C₃haloalkyl; and each R¹¹ is independentlyselected from hydrogen, C₁-C₃alkoxy and hydroxy.
 2. A compound of claim1, or a pharmaceutically acceptable salt thereof, wherein R¹ and R² areeach hydrogen.
 3. A compound of claim 1, or a pharmaceuticallyacceptable salt thereof, wherein one of R¹ and R² is C₁-C₃alkyl and theother is selected from hydrogen and C₁-C₃alkyl.
 4. A compound of claim1, or a pharmaceutically acceptable salt thereof, wherein one of R¹ andR² is hydrogen and the other is C₃-C₆cycloalkyl.
 5. A compound of claim1, or a pharmaceutically acceptable salt thereof, wherein R¹ and R²together are oxo; or R¹ and R², together with the carbon atom to whichthey are attached, form an oxetane ring.
 6. A compound of formula (II)

or a pharmaceutically acceptable salt thereof, wherein: R¹ and R² areindependently selected from hydrogen, C₃-C₆cycloalkyl, and C₁-C₃alkylwherein the C₁-C₃alkyl is optionally substituted with one, two, or threegroups independently selected from C₁-C₃alkoxy, C₁-C₃alkylamino, amino,cyano, C₁-C₃dialkylamino, halo, and hydroxy; or R¹ and R² together areoxo; R³ is C₁-C₃alkyl-Y or C₂-C₈alkyl, wherein the C₂-C₈alkyl isoptionally substituted with one, two, or three groups independentlyselected from C₁-C₃alkoxy, C₁-C₃alkylamino, C₁-C₃alkoxyC₂-C₃alkylamino,amino, aryl, halo, C₁-C₃haloalkylamino, C₁-C₃haloalkylcarbonylamino,hydroxy, —NR^(x)R^(y), and C₃-C₈cycloalkyl, wherein the cycloalkyl isfurther optionally substituted with one, two, or three groupsindependently selected from C₁-C₃alkoxy, C₁-C₃alkyl, C₁-C₃alkylamino,C₁-C₃alkoxyC₂-C₃alkylamino, amino, aryl, arylC₁-C₃alkyl, halo,C₁-C₃haloalkyl, C₁-C₃haloalkylamino and hydroxy; R⁴ is selected fromhydrogen, C₁-C₃alkoxy, C₁-C₃alkoxycarbonylamino, C₁-C₃alkyl,C₁-C₃alkylamino, C₁-C₃alkylcarbonylamino, amino, arylamino,arylcarbonylamino, C₃-C₆cycloalkylamino, C₃-C₆cycloalkylcarbonylamino,C₃-C₆cycloalkyloxy, halo, C₁-C₃haloalkoxy, C₂-C₃haloalkylamino,C₂-C₃haloalkylcarbonylamino, and hydroxy; R⁵ is selected from hydrogen,C₁-C₃alkyl, cyano, C₃cycloalkyl, and halo; R^(x) and R^(y), togetherwith the nitrogen atom to which they are attached, form a three- tosix-membered ring; and Y is selected from

wherein R⁶ is selected from hydrogen, C₁-C₆alkyl, C₃-C₆cycloalkyl, andC₁-C₆alkylcarbonyl; n is 0, 1, 2, or 3; each R⁷ is independentlyselected from hydrogen, C₁-C₆alkyl, aryl, arylC₁-C₃alkyl,C₃-C₆cycloalkyl, halo, and C₁-C₃haloalkyl; and each R⁸ is independentlyselected from hydrogen, C₁-C₃alkoxy and hydroxy.
 7. A compound selectedfrom: (R)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine;(R)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-3-phenylpropan-2-amine;(R)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)butan-2-amine;(S)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)butan-2-amine;(S)-1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine;(2S)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-amine;(2R)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-amine;(2S)-1-(5-cyclopropyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine;(2R)-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-amine;(2S)-1-(5-ethyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine;(S)-8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-5-one;(S)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-4-yl)acetamide(S)-8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-4-amine;(S)-1-(9-bromo-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine;8-((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-4-amine;(S)-1-((1-fluoro-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine;1-(5H-chromeno[3,4-c]pyridin-8-yloxy)-5,5,5-trifluoropentan-2-amine;(S)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide;(S)-4-methyl-1-(spiro[chromeno[3,4-c]pyridine-5,3′-oxetan]-8-yloxy)pentan-2-amine;(8-(((5)-2-amino-4-methylpentyl)oxy)-5-(chloromethyl)-5H-chromeno[3,4-c]pyridin-5-yl)methanol;(2S)-1-(9-bromo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine;8-((S)-2-amino-4-methylpentyloxy)-5-methyl-5H-chromeno[3,4-c]pyridine-9-carbonitrile;(S)-8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridine-9-carbonitrile;(2S)-1-cyclopentyl-3-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)propan-2-amine;(S)-8-(2-amino-4-methylpentyloxy)-9-bromo-5H-chromeno[3,4-c]pyridin-5-one;4-fluoro-4-methyl-1-(5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)pentan-2-amine;(2S)-1-((9-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine;(S)-1-(((R)-9-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine;(S)-1-(((5)-9-chloro-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine;(2S)-1-((9-bromo-5-(trifluoromethyl)-5H-chromeno[3,4-c]pyridin-8-yl)oxy)-4-methylpentan-2-amine;8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-2-amine;N-(8-(((S)-2-amino-4-methylpentyl)oxy)-5-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide;(2S)-1-(9-iodo-5-methyl-5H-chromeno[3,4-c]pyridin-8-yloxy)-4-methylpentan-2-amine;(S)—N-(8-((2-amino-4-methylpentyl)oxy)-9-chloro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide;(S)-8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-amine;(S)-8-((2-amino-4-methylpentyl)oxy)-4-methyl-5H-chromeno[3,4-c]pyridin-5-one;(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-methyl-5H-chromeno[3,4-c]pyridin-2-yl)acetamide;N-(8-((2-amino-5,5,5-trifluoropentyl)oxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide;(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-methoxy-5H-chromeno[3,4-c]pyridin-2-yl)acetamide;(S)—N-(8-(2-amino-4-methylpentyloxy)-7-(difluoromethyl)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide;(S)-4-methyl-1-((2-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-amine;(R)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide;(S)—N-(8-((2-amino-4-methylpentyl)oxy)-7-fluoro-5H-chromeno[3,4-c]pyridin-2-yl)acetamide;(S)—N-(8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)cyclopropanecarboxamide;(S)-methyl8-(2-amino-4-methylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-ylcarbamate;andN-(8-(2-amino-2,4-dimethylpentyloxy)-5H-chromeno[3,4-c]pyridin-2-yl)acetamide;or a pharmaceutically acceptable salt thereof.
 8. A compositioncomprising a pharmaceutically acceptable amount of a compound of claim1, or a pharmaceutically acceptable salt thereof, and a pharmaceuticallyacceptable carrier.
 9. A method of inhibiting adaptor associated kinase1 (AAK1) activity, comprising contacting AAK1 with a compound of claim1, or a pharmaceutically acceptable salt thereof.
 10. A method fortreating or managing a disease or a disorder mediated by AAK1 activity,the method comprising administering to a patient in need thereof atherapeutically effective amount of a compound of claim 1, or apharmaceutically acceptable salt thereof.
 11. The method of claim 10,wherein the disease or disorder is selected from Alzheimer's disease,bipolar disorder, pain, Parkinson's disease, and schizophrenia.
 12. Themethod of claim 11 wherein the pain is neuropathic pain.
 13. The methodof claim 12 wherein the neuropathic pain is fibromyalgia or peripheralneuropathy.